Science & Physics
Physics, chemistry, biology, earth and space science — the academic and curiosity cluster, from kinematics to orbital mechanics.
Physics, chemistry, biology, earth and space science in one hub. Kinematics, energy and momentum, thermodynamics, waves and optics, electricity and magnetism, relativity, and the quantum and nuclear calculations that used to sit in their own thin categories.
Chemistry covers molarity and dilution, stoichiometry, gas laws, pH and buffers, and reaction kinetics. Astronomy and space run from telescope limiting magnitude and observing planners through orbital mechanics, delta-v and rocket equations to life-support consumables.
Earth and ocean science, biology and biotech, forensics and archaeology complete the set — the calculations behind a lab report, a field survey or a homework problem.
246 calculators in 6 sections.
Start with these
The questions people most often bring to this page, and the calculator that answers each one.
- Ohm's Law Calculator — Solve voltage, current, resistance or power from any two.
- Voltage Drop Calculator — Conductor voltage drop over a run, by gauge and load.
- Resistor Color Code Calculator — Band colours to resistance and tolerance, both ways.
Matches are ranked by relevance. Use CtrlK anytime to search the full site.
Physics, Quantum & Nuclear
Mechanics, energy, waves, relativity, quantum states and radioactive decay.
Fluid Dynamics (Bernoulli) Calculator
Apply Bernoulli's equation to calculate pressure or velocity changes in an ideal fluid between two points at different heights.
Buoyancy Calculator
Calculate the buoyant force, net force, and whether an object floats or sinks using Archimedes' principle: F_b = ρ_fluid × V × g.
Capacitance Calculator
Calculate the capacitance of a parallel plate capacitor from plate area, separation, and dielectric constant using C = ε₀εᵣA/d.
Diffraction Grating Calculator
Calculate diffraction angles for each order using d sin(θ) = mλ. Find the maximum observable order and angular dispersion.
Doppler Effect Calculator
Calculate the observed frequency when a sound source and observer are in relative motion using the Doppler effect equation.
Electromagnetic Wave Calculator
Calculate the wavelength, photon energy, and momentum of an electromagnetic wave from its frequency using c = fλ and E = hf.
Inductance Calculator
Calculate the inductance of a solenoid from turns, length, cross-section area, and core permeability using L = μ₀μᵣN²A/l.
Magnetic Field Calculator
Calculate the magnetic field strength (B) for a straight wire, solenoid, or circular loop using Biot-Savart and Ampere's law.
Optics Lens Calculator
Calculate image distance, magnification, and image properties using the thin lens equation (1/f = 1/do + 1/di).
Pendulum Calculator
Calculate the period and frequency of a simple pendulum from its length and local gravitational acceleration using T = 2π√(L/g).
Projectile Motion Calculator
Calculate the range, maximum height, and flight time of a projectile given its initial velocity, launch angle, and initial height.
RC Circuit Time Constant Calculator
Calculate the time constant (τ = RC), voltage, and current at any time for an RC circuit during charging or discharging.
Relativistic Mechanics Calculator
Calculate time dilation, length contraction, relativistic mass, kinetic energy, and momentum from velocity as a fraction of the speed of light.
RLC Resonance Calculator
Calculate the resonant frequency, Q factor, and bandwidth of a series RLC circuit. Visualize the impedance curve.
Snell's Law Calculator
Calculate the refraction angle when light passes between two media using Snell's law: n₁ sin(θ₁) = n₂ sin(θ₂). Includes critical angle and Fresnel reflectance.
Centripetal Force Calculator
Force from mass, velocity, and radius.
Hooke's Law Calculator
Spring force, elastic potential energy, and oscillation period.
Torque Calculator
Torque from force, lever arm, and angle with unit conversions.
Momentum Calculator
Linear momentum, impulse, and kinetic energy from mass and velocity.
Work-Energy Calculator
Work, kinetic energy, and power from force and displacement.
Gravitational Force Calculator
Newton's law of universal gravitation: F = Gm1m2/r².
Electric Field Calculator
Electric field, force, and potential from charge and distance.
Wave Speed Calculator
Wave speed from frequency and wavelength (v = fλ).
Elastic Collision Calculator
Final velocities and energy transfer in 1D elastic collisions.
Simple Harmonic Motion Calculator
Displacement, velocity, and acceleration at any time in SHM.
Terminal Velocity
v = √(2mg/(ρ C_d A)) at steady drag = weight.
Ohm's Law Current Calculator
Calculate electric current from voltage and resistance using Ohm's law (I = V / R).
Wave Function Calculator
Calculate quantum wave function properties including probability density, momentum, energy, and phase/group velocities.
Probability Amplitude Calculator
Calculate quantum probability amplitudes, Born rule probabilities, phase angles, and normalization.
Uncertainty Principle Calculator
Calculate Heisenberg uncertainty limits for position-momentum and energy-time conjugate pairs.
Quantum Tunneling Calculator
Calculate quantum tunneling probability, transmission coefficient, and penetration depth through a potential barrier.
Quantum Entanglement Calculator
Calculate quantum entanglement measures including concurrence, von Neumann entropy, tangle, and Bell state fidelity.
Schrodinger Equation Calculator
Calculate energy eigenvalues, wave functions, and quantum states for infinite wells and harmonic oscillators.
Quantum Energy Levels Calculator
Calculate atomic energy levels, transition energies, photon wavelengths, and spectral series for hydrogen-like atoms.
Quantum Measurement Calculator
Calculate quantum measurement probabilities, expectation values, variance, and wave function collapse.
Quantum Superposition Calculator
Calculate quantum superposition states, interference effects, coherence, and phase relationships.
Quantum Gate Calculator
Calculate quantum gate operations, output states, probabilities, and gate fidelity for quantum computing.
Quantum Decoherence Calculator
Calculate quantum decoherence time, coherence decay, purity, and fidelity degradation for quantum systems.
Quantum Teleportation Calculator
Calculate quantum teleportation fidelity, success probability, resource requirements, and teleportation quality.
Quantum Foundations Calculator
Fundamental quantum mechanics calculations. Wave-particle duality, Heisenberg uncertainty, quantum harmonic oscillator, hydrogen atom, and spin.
Quantum Phenomena Calculator
Quantum phenomena calculations. Tunneling, photoelectric effect, Compton scattering, blackbody radiation, and quantum entanglement.
Quantum Computing Calculator
Complete quantum computing analysis. Qubit states, quantum gates, algorithm complexity, error correction, and hardware platforms.
De Broglie λ
λ = h / (mv) for non-relativistic momentum.
Criticality Calculator
Estimate neutron multiplication factor from geometry, enrichment, moderation, and reflection parameters.
Decay Chain Calculator
Calculate daughter nuclide activity buildup and decay from parent decay using the Bateman equation.
Decontamination Factor Calculator
Calculate decontamination factor and efficiency from before and after contamination measurements.
Radiation Dose Rate Calculator
Calculate radiation dose rate from source activity and distance using the inverse square law.
Isotope Production Calculator
Calculate activity produced from neutron irradiation given flux, cross section, and irradiation time.
Nuclear Fuel Burnup Calculator
Calculate energy extracted from nuclear fuel assemblies by burnup level in MWd/MTU.
Nuclear Waste Classification Calculator
Classify radioactive waste per 10 CFR 61 from radionuclide concentrations using sum-of-fractions.
Radiation Exposure Tracking Calculator
Track cumulative radiation dose against annual occupational limits and ALARA targets.
Radioactive Decay Calculator
Calculate remaining radioactive activity from initial activity, half-life, and elapsed time.
Radiation Shielding Calculator
Calculate required shield thickness for target dose reduction using half-value and tenth-value layers.
Ohm's Law Calculator
Calculate voltage, current, resistance, or power using Ohm's Law (V = I × R). Enter any two values to find the others.
Voltage Drop Calculator
Calculate voltage drop in electrical wiring based on wire gauge, length, current, and material. Ensure your circuits meet NEC recommendations.
Force Calculator (F=ma)
Calculate force, mass, or acceleration using Newton's Second Law (F = ma). Includes unit conversions to pounds-force and dynes.
Density Calculator
Calculate density, mass, or volume using the formula ρ = m/V. Includes a reference table of common material densities.
Molar Mass Calculator
Calculate molar mass, convert between grams and moles, and find the number of molecules for elements and common compounds.
Wavelength & Frequency Calculator
Convert between wavelength and frequency. Calculate photon energy and identify the electromagnetic spectrum band.
Resistor Color Code Calculator
Decode resistor color bands to find resistance value, tolerance range, and minimum/maximum resistance. Includes color code reference table.
pH Calculator
Calculate pH, pOH, hydrogen ion concentration, and hydroxide concentration. Determine if a solution is acidic, neutral, or basic.
Velocity & Acceleration Calculator
Solve kinematics problems using equations of motion. Calculate velocity, acceleration, time, or distance from the other known values.
Chemical Equation Balancer
Balance chemical equations and calculate stoichiometry. Find limiting reactants and product yields.
Kinetic Energy Calculator
Calculate kinetic energy from mass and velocity. Use the formula KE = ½mv².
Potential Energy Calculator
Calculate gravitational potential energy from mass and height. Use the formula PE = mgh.
Momentum Calculator
Calculate momentum from mass and velocity. Use the formula p = mv.
Power Calculator
Calculate power from work and time, or force and velocity. Use formulas P = W/t or P = Fv.
Electrical Engineering Suite
Complete electrical calculator — Ohm's Law, voltage drop, resistor color codes, series/parallel circuits, and capacitor calculations for engineers and hobbyists.
Physics Essentials Calculator
Complete classical mechanics calculator — force, velocity, acceleration, kinetic/potential energy, momentum, power, and projectile motion calculations.
Chemistry & Nanotechnology
Molarity, stoichiometry, gas laws, pH and nanoscale material properties.
Molarity Calculator
Calculate the molarity (molar concentration) of a solution from solute mass, molar mass, and solution volume. Essential for chemistry lab work and solution preparation.
Molecular Weight Calculator
Calculate the molecular weight (molar mass) of chemical compounds from their formula. Shows element-by-element breakdown with atomic weights.
Boiling Point Elevation
Calculate the boiling point elevation of a solution from the ebullioscopic constant, molality, and van't Hoff factor.
Buffer Solution Calculator
Calculate buffer pH using the Henderson-Hasselbalch equation. Enter pKa, acid concentration, and conjugate base concentration.
Calorimetry Calculator
Calculate heat energy (q) from mass, specific heat capacity, and temperature change using the calorimetry equation q = mcΔT.
Dilution Calculator (C1V1=C2V2)
Calculate required volumes for solution dilution using the C1V1 = C2V2 equation. Essential for lab work and preparing standard solutions.
Electrochemistry Cell Potential
Calculate electrochemical cell potential using standard reduction potentials and the Nernst equation. Includes Gibbs free energy and equilibrium constant.
Electron Configuration Generator
Generate the electron configuration for any element by atomic number. Follows the Aufbau principle to fill s, p, d, and f orbitals.
Empirical Formula Finder
Determine the empirical formula of a compound from elemental percent composition. Supports C, H, O, and N.
Equilibrium Constant Calculator
Calculate the equilibrium constant (Keq) from product and reactant concentrations with stoichiometric coefficients. Includes Gibbs free energy.
Freezing Point Depression
Calculate the freezing point depression of a solution from the cryoscopic constant, molality, and van't Hoff factor.
Ideal Gas Law Calculator
Solve PV = nRT for any unknown variable — pressure, volume, moles, or temperature. Includes isothermal P-V curve visualization.
Molarity Calculator
Calculate molarity (moles per liter) from mass, molecular weight, and solution volume. Essential for preparing laboratory solutions.
Osmotic Pressure Calculator
Calculate osmotic pressure using the van't Hoff equation (π = iMRT). Convert between atm, kPa, mmHg, and psi.
Reaction Rate Calculator
Calculate reaction rate from rate constant, reactant concentrations, and reaction orders using the rate law equation.
Stoichiometry Calculator
Calculate product mass from reactant mass using molecular weights and mole ratios. Supports percent yield for practical lab calculations.
Titration Calculator
Calculate the equivalence point volume for acid-base titrations. Includes an interactive titration curve for strong acid-strong base reactions.
pH to [H⁺]
Hydronium molarity from pH at 25 °C (Kw = 10⁻¹⁴).
Nanoparticle Size Calculator
Size distribution processing from lab inputs.
Surface-to-Volume Ratio Calculator
S/V ratio for spheres, cubes, and cylinders at nanoscale.
Quantum Dot Calculator
Emission wavelength and bandgap from quantum dot size (Brus equation).
Thin Film Thickness Calculator
Film thickness from deposition rate and time, with optical properties.
Nanomaterial Concentration Calculator
Particle count, molarity, and surface area from mass concentration.
Self-Assembly Calculator
Packing parameter and predicted self-assembled structure.
AFM Tip Convolution Calculator
Deconvolved feature width from AFM tip radius correction.
Nanopore Flow Calculator
Flow rate through nanopores with slip correction.
Nanocomposite Property Calculator
Modulus, density, and percolation threshold for nanocomposites.
Nanoscale Heat Transfer Calculator
Effective thermal conductivity and Knudsen regime at nanoscale.
Astronomy, Space & Rocketry
Orbits and delta-v, telescope optics, observing planning and life support.
Orbital Period Calculator
Calculate orbital period using Kepler's laws. Find orbital velocity, angular velocity, and perihelion/aphelion distances.
Escape Velocity Calculator
Calculate escape velocity, orbital velocity, and gravitational parameters for celestial bodies.
Stellar Luminosity Calculator
Calculate stellar luminosity using Stefan-Boltzmann law. Find absolute magnitude, main sequence lifetime, and stellar parameters.
Redshift Calculator
Calculate cosmological redshift, recessional velocity, distance, and lookback time using Hubble's law.
Black Hole Event Horizon Calculator
Calculate Schwarzschild radius, event horizon, ergosphere, Hawking temperature, and black hole parameters.
Planetary Transit Calculator
Calculate transit depth, duration, probability, and timing for exoplanet transits.
Stellar Mass Calculator
Calculate stellar mass using mass-luminosity relation, mass-radius relation, and orbital dynamics.
Cosmological Distance Calculator
Calculate luminosity distance, comoving distance, angular diameter distance, and lookback time using cosmological models.
Tidal Force Calculator
Calculate tidal forces, Roche limit, Hill sphere, and tidal locking timescales for celestial bodies.
Roche Limit Calculator
Calculate Roche limit - the minimum distance a satellite can orbit before being torn apart by tidal forces.
Stellar Physics Calculator
Complete stellar physics calculations. Analyze luminosity, temperature, nuclear fusion, stellar evolution, black body radiation, and stellar distances.
Orbital Mechanics Calculator
Complete orbital mechanics calculations. Kepler's laws, Hohmann transfers, delta-v, Lagrange points, escape velocities, and relativistic effects.
Cosmology Suite Calculator
Complete cosmology calculations. Hubble's law, cosmic distances, Big Bang timeline, dark matter/energy, CMB analysis, and black hole physics.
Escape Velocity
v_esc = √(2GM/R) from mass and radius.
Planck Bλ
Blackbody spectral radiance per unit wavelength (SI).
Stefan–Boltzmann
P = εσAT⁴.
Hubble Time
Order-of-magnitude Hubble time 1/H0 from H₀ in km/s/Mpc.
Drake Equation
N = R⋅fp⋅ne⋅fl⋅fi⋅fc⋅L (your parameter guesses).
Asteroid Impact Energy
Calculate the kinetic energy and destructive potential of an asteroid impact from diameter, velocity, and density. Estimates crater size and earthquake equivalent.
Astrophotography Exposure
Calculate the maximum untracked exposure time to avoid star trails using the NPF rule, 500 rule, and declination correction.
Binary Star Orbit
Calculate the total mass of a binary star system from orbital period and semi-major axis using Kepler's Third Law.
Exoplanet Habitability Score
Calculate the Earth Similarity Index (ESI) for an exoplanet based on radius, density, escape velocity, and surface temperature relative to Earth.
Hubble's Law Calculator
Calculate recession velocity and distance from cosmological redshift using Hubble's Law. Includes lookback time, scale factor, and relativistic corrections.
Light Travel Time
Calculate how long light takes to travel a given distance. Enter distance in AU or km and get travel time in seconds, minutes, hours, days, or years.
Solar Eclipse Timing
Calculate solar eclipse duration and umbral shadow diameter from Moon and Sun distances. Determines eclipse type, angular sizes, and maximum totality duration.
Star Magnitude Calculator
Calculate absolute magnitude from apparent magnitude and distance using the distance modulus formula. Includes luminosity ratio and parallax.
Telescope Limiting Magnitude
Calculate the faintest star visible through a telescope based on aperture and sky brightness conditions.
Telescope Magnification
Calculate telescope magnification, true field of view, exit pupil, and resolution from focal length, eyepiece, and apparent field of view.
Age on Other Planets
Find out how old you would be on every planet in our solar system. Your age depends on each planet's orbital period around the Sun.
Collimation Calculator
Calculate secondary mirror offset and collimation tolerance for Newtonian reflectors.
Comet Brightness Calculator
Predict a comet's apparent magnitude based on absolute magnitude and distances from Earth and Sun.
Deep Sky Finder Calculator
Estimate how many galaxies, nebulae, and star clusters are observable with your telescope from your location.
Eyepiece Collection Calculator
Plan a 3-eyepiece set for your telescope with low, medium, and high power focal lengths.
Light Pollution Calculator
Estimate naked-eye and telescope limiting magnitude and SQM reading based on Bortle class, altitude, and moon phase.
Meteor Shower Calculator
Predict how many meteors you will actually see per hour based on shower ZHR, radiant altitude, and sky conditions.
Mount Payload Calculator
Check if your telescope and accessories are within your mount's payload capacity for visual or imaging use.
Solar Filter Calculator
Size a solar filter for safe sun observation and estimate solar image size and cost by filter type.
Star Party Planner Calculator
Plan a star party by estimating sunset time, moon phase, visible planets, and observable deep-sky objects for your location and date.
Telescope Comparison Calculator
Compare two telescopes by f/ratio, light-gathering power, and angular resolution.
CubeSat Budget Calculator
Build cost, launch cost, and operations for CubeSat missions.
Orbit Determination Calculator
Orbital elements from position and velocity vectors.
Ground Station Pass Duration Calculator
Visible pass time from orbit altitude and station latitude.
Space Debris Risk Calculator
Collision probability from object density and orbital altitude.
Constellation Design Calculator
Satellite count for global coverage from altitude and inclination.
Launch Vehicle Selection Calculator
Payload capacity comparison across launch providers.
Spacecraft Thermal Calculator
Temperature range from solar flux, albedo, and surface properties.
Communication Latency Calculator
Signal delay from satellite altitude for LEO, MEO, and GEO.
Orbital Lifetime Calculator
Orbital decay time from altitude and ballistic coefficient.
Space Mission Cost Estimator Calculator
Total mission cost from spacecraft mass and destination.
Rocket Motor Selection Calculator
Determine the right NAR motor class for your rocket based on mass, target altitude, and drag estimates using energy-based delta-V and impulse calculations.
Recovery System Calculator
Size your rocket parachute for a safe descent rate. Calculates canopy diameter, area, landing energy, and drift distance using aerodynamic drag equations.
Stability Calculator (Rocket)
Calculate your rocket's static stability margin using the Barrowman equations. Determines CP and CG separation in calibers for safe flight.
Fin Flutter Speed Calculator
Calculate the critical flutter velocity for rocket fins based on material shear modulus, fin geometry, and altitude using the NARTS approximation.
Launch Lug Sizing Calculator
Calculate rod/rail exit velocity and minimum guide length for a safe launch. Accounts for thrust, gravity, friction, and wind speed.
Motor Retention Calculator
Calculate ejection and deceleration forces on your rocket motor to choose the right retention method -- friction fit, tape, clip, or threaded retainer.
Altimeter Bay Design Calculator
Design your rocket's avionics bay. Calculate internal volume, verify component fit, and size vent holes for accurate barometric altitude readings.
Dual Deploy Calculator
Size drogue and main parachutes for dual-deployment recovery. Calculates chute diameters, descent times, opening shock, and black powder ejection charges.
Rocket Drag Coefficient Calculator
Estimate total Cd by summing nose, body, base, fin, and interference drag using semi-empirical methods from Hoerner and Mandell/Caporaso/Bengen.
High-Power Certification Calculator
Plan your NAR/TRA Level 1, 2, or 3 certification flight. Predicts altitude, velocity, and Mach number from motor and rocket specifications.
CO2 Scrubbing Calculator
Size CO2 removal systems for space habitats comparing LiOH, CDRA, and Sabatier technologies.
Oxygen Generation Calculator
Calculate O2 requirements, electrolysis water needs, and power for crew oxygen generation in space habitats.
Water Recycling Efficiency Calculator
Calculate water needs with and without recycling, autonomy days, and launch mass savings for space missions.
Radiation Shielding Calculator
Calculate radiation dose reduction from shielding material type, thickness, and solar activity level.
Food Supply Duration Calculator
Calculate food mass, packaging, storage volume, and waste for space mission provisioning.
Waste Management Capacity Calculator
Size waste processing, storage, and water recovery systems for space habitat waste management.
Habitat Volume Calculator
Size pressurized habitat volume based on crew, mission duration, comfort level, and equipment needs.
Thermal Control System Calculator
Size radiators and thermal control for space habitats based on crew, equipment heat, and solar exposure.
Artificial Gravity Calculator
Calculate rotation rate, gravity gradient, and comfort rating for centripetal artificial gravity systems.
Bioregenerative Life Support Calculator
Calculate food production, O2 output, and self-sufficiency from crop growing area in space habitats.
Earth & Ocean Science
Rock and strata, seismic and volcanic measures, tides, waves and marine life.
Earthquake Distance Calculator
Epicenter distance from P-wave and S-wave arrival times.
Volcano Hazard Zone Calculator
Hazard radius from eruption type and VEI.
Landslide Risk Calculator
Slope stability factor from soil, angle, and water table.
Glacial Retreat Calculator
Retreat rate from historical measurements and temperature.
Paleoclimate Proxy Converter Calculator
Temperature from oxygen isotope ratios (delta18O).
River Meandering Calculator
Migration rate from channel width and discharge.
Karst Feature Calculator
Sinkhole risk from limestone depth and water table.
Magnetic Declination Calculator
Declination correction from location and date.
Fossil Age Estimator Calculator
Age range from stratigraphic layer and index fossils.
Continental Drift Calculator
Distance between landmasses from plate motion rate and time.
Groundwater Flow (Darcy's Law)
Calculate groundwater flow rate using Darcy's Law from hydraulic conductivity, hydraulic gradient, and cross-sectional area.
Geologic Time Scale Calculator
Look up the geologic period, era, and eon for any age in millions of years ago (Ma) using the international geologic time scale.
Mineral Identification Score
Identify likely minerals based on hardness, luster, cleavage, and color group using a scoring system against common mineral profiles.
Ore Grade Calculator
Calculate recoverable metal tonnage from total ore tonnage, grade percentage, recovery rate, and cutoff grade.
Plate Tectonic Rate Calculator
Calculate tectonic plate movement rate in cm/year from total displacement distance and time span in millions of years.
Rock Density Calculator
Calculate bulk density, grain density, and porosity from dry, saturated, and submerged mass measurements.
Sediment Transport Calculator
Calculate bedload transport rate, shear stress, and transport mode from stream velocity, grain size, water depth, and slope.
Seismic Magnitude Converter
Convert seismic magnitude to energy released (Joules, TNT equivalent) and Modified Mercalli Intensity (MMI).
Strike and Dip Calculator
Calculate apparent dip from true dip and the angle between the strike direction and cross-section line.
Well Drawdown Calculator
Calculate well drawdown using the Theis/Cooper-Jacob equation from pump rate, transmissivity, storage coefficient, time, and distance.
Bathymetric Profile Calculator
Calculate average depth, seafloor slope, and gradient from start/end depths and horizontal distance.
Coral Bleaching Risk Calculator
Assess coral bleaching risk using Degree Heating Weeks (DHW) based on sea surface temperature anomalies and duration above threshold.
Marine Sound Propagation Calculator
Calculate the speed of sound in seawater from temperature, salinity, and depth using the Mackenzie equation.
Ocean Current Speed Calculator
Calculate geostrophic current velocity from pressure gradient, latitude, and water density using Coriolis-adjusted equations.
Sea Level Rise Impact Calculator
Estimate coastal inundation area and shoreline retreat from sea level rise based on coastline length, slope, and rise amount.
Seawater Density Calculator
Calculate seawater density from temperature, salinity, and pressure using a simplified UNESCO equation of state.
Tidal Range Predictor
Predict spring and neap tidal ranges from mean tidal range, lunar phase, and solar declination factor.
Tsunami Travel Time Calculator
Calculate tsunami propagation speed and arrival time from ocean depth and distance using shallow water wave theory (v = √(g·d)).
Upwelling Index Calculator
Calculate coastal upwelling index from wind stress, latitude, and water density using Ekman transport theory.
Wave Height & Period Calculator
Calculate significant wave height, period, and wavelength from wind speed, fetch distance, and duration using the SMB method.
Fish Population Estimate Calculator
Estimate fish population size using the Lincoln-Petersen mark-recapture method with Chapman correction and 95% confidence intervals.
Coral Growth Rate Calculator
Model coral colony linear extension rate based on species growth baseline, water temperature, light (PAR), and aragonite saturation state.
Marine Protected Area Size Calculator
Estimate minimum MPA size from species home range, viable population targets, species-area relationships, and protection level requirements.
Whale Migration Calculator
Estimate cetacean migration distance, travel time, and energy expenditure based on breeding/feeding ground coordinates, swim speed, and body mass.
Plankton Biomass Calculator
Calculate plankton cell density and carbon biomass from net tow or water sample counts using standard oceanographic methods.
Seagrass Restoration Calculator
Plan seagrass restoration projects: estimate shoot requirements, labor, costs, carbon sequestration, and ecosystem service value.
Fish Biodiversity Index Calculator
Calculate Shannon-Wiener diversity (H'), Simpson's index, Pielou's evenness, and Margalef's richness from species abundance data.
Bycatch Rate Calculator
Calculate bycatch ratio, discard rate, BPUE, and fleet-wide bycatch estimates from fishing operation data for fisheries management.
Aquatic Toxicology Calculator
Estimate LC50 from two dose-response data points using probit approximation. Calculate toxic units, PNEC, and environmental risk quotient.
Mangrove Carbon Stock Calculator
Estimate mangrove ecosystem carbon stock from tree measurements, soil properties, and area using allometric equations (Komiyama et al. 2005).
Biology & Biotechnology
Population genetics, cell culture, PCR and bioprocess yields.
Beer-Lambert Law Calculator
Calculate concentration from absorbance using the Beer-Lambert law (A = εlc). Also computes transmittance.
Cell Doubling Time
Calculate cell doubling time, growth rate, and generation count from optical density measurements over time.
Dilution Plating Calculator
Calculate colony-forming units per mL (CFU/mL) from colony count, dilution factor, and volume plated.
DNA/RNA Molecular Weight
Calculate the molecular weight of DNA or RNA from nucleotide count and type (dsDNA, ssDNA, ssRNA).
Enzyme Kinetics (Michaelis-Menten)
Calculate reaction velocity from Vmax, Km, and substrate concentration using the Michaelis-Menten equation.
Hardy-Weinberg Calculator
Calculate genotype frequencies (p², 2pq, q²) from allele frequencies using the Hardy-Weinberg equilibrium equation.
Hemocytometer Cell Count
Calculate cell concentration (cells/mL) from hemocytometer counts, number of squares, and dilution factor.
PCR Primer Calculator
Calculate melting temperature (Tm), GC content, and annealing temperature for PCR primers.
Protein Molecular Weight
Estimate protein molecular weight from amino acid count and post-translational modifications.
Punnett Square Generator
Calculate offspring genotype and phenotype ratios from parent genotypes using a Punnett square for monohybrid crosses.
Bioreactor Sizing Calculator
Determine bioreactor working volume from production targets, cell density, and specific productivity for CHO, HEK293, and other cell lines.
Fermentation Scale-Up Calculator
Scale bioreactor parameters from lab to production using constant tip speed or constant P/V strategies.
Purification Yield Calculator
Calculate overall downstream purification yield from individual step recoveries for biologics manufacturing.
Cell Bank Calculator
Calculate vial count, expansion time, and storage requirements for master and working cell banks.
Media Preparation Calculator
Calculate reagent volumes for cell culture media batches using C1V1 = C2V2 dilution.
Protein Concentration Calculator
Protein quantification from Bradford/BCA assay data using Beer-Lambert Law (A = εlc).
Viral Titer Calculator
Calculate viral titer (PFU/mL) from plaque assay data and determine volume needed for target MOI.
Gene Therapy Dose Calculator
Calculate total vector genome dose from patient weight and target vg/kg for AAV and lentiviral gene therapies.
Stability Study Design Calculator
Calculate total sample count from time points, conditions, tests, replicates, and batches per ICH Q1A(R2).
Cleanroom Classification Calculator
Calculate particle count limits by ISO 14644-1 cleanroom class with EU GMP grade mapping.
Forensics & Archaeology
Trajectory and blood spatter, time of death, radiocarbon and site sampling.
Blood Spatter Analysis Calculator
Calculate bloodstain impact angle, area of origin, and droplet velocity from stain dimensions. Uses the sine-ratio method for angle determination.
Bullet Trajectory Calculator
Calculate bullet trajectory angle, estimated muzzle distance, and bullet drop from entry/exit hole positions and distance between surfaces.
Digital Forensics File Timeline Calculator
Analyze file system activity patterns to detect anomalies. Calculates activity rate, deletion ratio, and an anomaly score indicating potential anti-forensic behavior.
DNA Match Probability Calculator
Calculate random match probability and likelihood ratio for DNA evidence based on loci matched, population size, and allele frequencies.
Document Age Estimation Calculator
Estimate document age from ink volatile analysis and paper acidity. Uses exponential decay modeling of ink solvent evaporation.
Fingerprint Ridge Count Calculator
Classify fingerprint patterns using ridge count and the Henry system. Determine pattern frequency and print quality assessment.
Fire Origin & HRR Calculator
Estimate heat release rate, flashover time, and ventilation control for fire investigation. Uses Thomas correlations and t-squared growth models.
Forensic Accounting Calculator
Detect financial discrepancies using the net worth method. Compare reported income against bank deposits, expenses, and asset accumulation.
Time of Death Calculator
Estimate post-mortem interval (PMI) using body temperature, ambient temperature, body weight, and clothing. Based on Newton's Law of Cooling.
Toxicology Dose Back-Calculator
Back-calculate an ingested dose from blood concentration using volume of distribution and elimination kinetics. Estimate peak concentration and elimination time.
Artifact Classification Score Calculator
Score artifacts using type-variety classification from morphological attributes and contextual data.
Artifact Density Calculator
Calculate objects per cubic meter and per square meter from excavation unit dimensions and artifact counts.
Burial Depth Estimator
Estimate expected artifact burial depth from site age, depositional rate, and geomorphological context.
Ceramic Temper Analysis Calculator
Analyze ceramic thin section point counts to determine temper type, proportion, and porosity.
Heritage Impact Assessment Calculator
Score development risk to archaeological sites from proximity, project type, and site significance.
Lithic Reduction Sequence Calculator
Classify a stone flake into reduction stages based on platform type, cortex, and dorsal scar attributes.
Radiocarbon Date Calibrator
Convert radiocarbon years BP to approximate calendar age with uncertainty ranges and reservoir correction.
Site Preservation Cost Calculator
Estimate conservation cost for an archaeological site based on area, threat level, and preservation method.
Stratigraphy Volume Calculator
Calculate excavation volume from layer dimensions and variable depth across the unit.
Survey Transect Calculator
Calculate survey coverage percentage from transect spacing, width, and survey area size.