Environment, Weather & Climate
Weather and climate, air and water quality, ecology and conservation, waste management and site remediation.
Weather, climate and the environment measured rather than described. Heat index and wind chill, dew point and humidity, storm and snowfall estimates, growing degree days, and the seasonal averages behind them.
Air and water quality covers AQI conversion, emission rates, dispersion, dosing and disinfection contact time, and catchment runoff and detention volumes.
Ecology, conservation and wildlife management supply population and habitat estimates; waste management and remediation cover diversion rates, landfill volumes, contaminated soil quantities and cleanup costing.
144 calculators in 4 sections.
Start with these
The questions people most often bring to this page, and the calculator that answers each one.
- Sludge Volume Calculator — Sludge volume, dry solids mass and percent solids.
- Chlorine Dosing Calculator — Chlorine dose, demand and residual for a treatment train.
Matches are ranked by relevance. Use CtrlK anytime to search the full site.
Weather & Climate
Heat index, wind chill, dew point, storm estimates and climate normals.
Heat Index Calculator
Calculate the heat index (feels-like temperature) based on air temperature and humidity. Assess heat danger level.
Dew Point Calculator
Calculate the dew point temperature from air temperature and relative humidity. Includes comfort level assessment and frost risk.
USDA Growing Zone Calculator
Find your USDA Plant Hardiness Zone based on average annual extreme minimum temperature. Know what plants will thrive in your area.
Snow Load Calculator
Calculate roof snow load in PSF based on snow depth, type, and roof pitch. Assess structural risk level.
Daylight Hours Calculator
Calculate sunrise, sunset, and total daylight hours for any location and date. See monthly daylight patterns.
Rainfall & Irrigation Calculator
Calculate lawn irrigation needs based on rainfall, lawn size, and target watering. See weekly water deficit, watering time, and cost.
Frost Date Calculator
Find estimated last spring frost and first fall frost dates by USDA hardiness zone. Plan your garden planting window with confidence.
UV Index Calculator
Assess UV exposure risk based on UV index, skin type, altitude, and snow cover. Get personalized burn time and SPF recommendations.
Wind Speed Converter
Convert wind speed between mph, km/h, m/s, and knots. See Beaufort scale rating and wind description.
Humidity Calculator
Calculate relative humidity from temperature and dew point. Understand comfort levels and weather conditions.
Temperature Comfort Index Calculator
Complete weather comfort calculator — calculate wind chill, heat index, dew point, and feels-like temperature. Assess safety risks and get clothing/hydration recommendations.
Wind Chill Calculator
Calculate the wind chill temperature using the official NWS formula. Assess frostbite risk based on conditions.
Feels Like Temperature Calculator
Calculate the 'feels like' temperature considering wind chill and heat index. Understand perceived temperature.
CAPE and CIN Calculator
Calculate Convective Available Potential Energy (CAPE) and Convective Inhibition (CIN) from parcel and environmental temperatures at multiple pressure levels.
Drought Index Calculator
Estimate a Palmer Drought Severity Index (PDSI) category from temperature, precipitation, and soil moisture data. Includes water balance analysis and impact assessment.
Heat Index Deep Calculator
Calculate the heat index using the full Rothfusz regression equation with NWS adjustments. Includes risk assessment and exposure-duration guidance.
Lightning Distance Calculator
Calculate the distance to a lightning strike from the flash-to-bang time delay. Includes temperature-adjusted speed of sound and safety guidance.
Precipitation Type Forecaster
Forecast precipitation type (rain, snow, sleet, freezing rain) from temperatures at multiple atmospheric levels. Uses the thermal profile warm-nose method.
Skew-T Log-P Reader
Estimate atmospheric stability parameters from surface observations and upper-air data. Calculates CAPE, LCL, LFC, and Lifted Index using simplified thermodynamic profiles.
Tornado Risk Calculator
Calculate the Significant Tornado Parameter (STP) and Supercell Composite Parameter from CAPE, wind shear, storm-relative helicity, and LCL height.
Visibility Calculator
Estimate atmospheric visibility from humidity, precipitation rate, and particulate concentration. Provides aviation flight category and driving safety guidance.
Wet Bulb Globe Temperature
Calculate the Wet Bulb Globe Temperature (WBGT), the gold standard for heat stress assessment. Provides military/OSHA flag color, work-rest cycles, and hydration guidance.
Wind Power Density
Calculate wind power density (W/m²) from average wind speed, air density, and Weibull shape factor. Includes NREL wind class and sample turbine output estimates.
Carbon Footprint Calculator
Personal annual CO2 from transport, home, food, and goods.
Emission Reduction Calculator
CO2 savings from specific lifestyle changes.
Climate Model Interpreter Calculator
Temperature and radiative forcing from greenhouse gas concentrations using Myhre et al. formulas.
Sea Ice Extent Calculator
Arctic sea ice area trends from satellite data.
Greenhouse Gas Converter Calculator
CO2 equivalent from methane, N2O, and other GHGs.
Permafrost Thaw Calculator
Thaw depth projection from temperature and soil type.
Urban Heat Island Calculator
Temperature differential from land cover and albedo.
Climate Migration Risk Calculator
Community climate risk scoring from exposure and vulnerability.
Renewable Energy Mix Calculator
Optimal generation mix for target carbon reduction.
Climate Action ROI Calculator
Cost-benefit of climate mitigation actions.
Air & Water Quality
AQI and emissions, dispersion, treatment dosing, runoff and catchment yield.
AQI Calculator
Air Quality Index from pollutant concentrations (PM2.5, PM10, O3, CO, SO2, NO2) using EPA breakpoint tables.
Indoor Air Quality Score Calculator
IAQ assessment from CO2, VOC, humidity, and particulates.
HVAC Filtration Efficiency Calculator
MERV rating selection from particle size targets.
Air Purifier Sizing Calculator
CADR needed from room size and air changes per hour.
Vehicle Emissions Calculator
Annual emissions from vehicle type, age, and mileage.
Stack Emission Rate Calculator
Mass emission rate from stack testing data.
Dispersion Modeling Calculator
Downwind concentration from AERMOD-style Gaussian dispersion.
Greenhouse Gas Inventory Calculator
Scope 1, 2, and 3 emissions for organizational GHG inventory.
Carbon Capture Calculator
CO2 captured from CCS technology and capacity.
Dust Control Calculator
Water application rate for construction site dust suppression.
Air Change Rate Calculator
Calculate air changes per hour (ACH) from airflow rate and room volume with recommendations by room type.
Carbon Footprint Offset Calculator
Estimate your annual CO₂ footprint from electricity, driving, flights, and diet, with tree and cost offsets.
Dust Particle Settling Calculator
Calculate particle settling velocity and time using Stokes' law with Cunningham slip correction.
Emission Rate Calculator
Calculate source emission rate from measured indoor concentration, ventilation rate, and room volume.
Filtration Efficiency Calculator
Calculate MERV/HEPA filter efficiency, CADR, penetration, and pressure drop for different particle sizes.
Indoor CO₂ Calculator
Model indoor CO₂ buildup from occupancy and ventilation. Find steady-state levels and time to reach 1,000 ppm.
Mold Risk Calculator
Assess mold growth risk from humidity, temperature, surface type, and ventilation quality with dew point analysis.
Radon Mitigation Calculator
Estimate post-mitigation radon levels, system costs, and health risk reduction for different mitigation approaches.
Ventilation Dilution Calculator
Calculate required dilution ventilation to control airborne contaminants below TLV/PEL limits.
Backwash Water Calculator
Calculate filter backwash volume, frequency, and supply requirements for water treatment plant filter maintenance.
Chlorine Dosing Calculator
Calculate chlorine dose and feed rate for water disinfection, including CT compliance for pathogen inactivation.
Coagulant Dosing Calculator
Calculate alum, ferric chloride, or PACl feed rates from jar test results. Estimate alkalinity consumption and sludge production.
Corrosion Control Calculator
Calculate the Langelier Saturation Index (LSI) and Ryznar Stability Index for pipe corrosion prevention in drinking water.
Filtration Rate Calculator
Calculate filter area, media volume, and backwash requirements from flow rate and loading rate.
Fluoride Addition Calculator
Calculate chemical feed rate for water fluoridation to achieve target concentration using NaF, fluorosilicic acid, or sodium fluorosilicate.
Membrane Flux Calculator
Calculate permeate flux, transmembrane pressure, and fouling indicators for membrane filtration systems (MF/UF/NF/RO).
Sludge Volume Calculator
Estimate sludge production from water treatment including turbidity removal and chemical addition. Size lagoons and estimate disposal costs.
UV Disinfection Calculator
Calculate UV dose and reactor sizing for pathogen inactivation based on flow rate, UVT, and target log reduction.
Water Treatment Plant Sizing Calculator
Size a water treatment plant from population, per-capita demand, and peak factors. Estimate basin, filter, and clearwell dimensions.
Dam Spillway Design
Calculate spillway discharge capacity using the weir equation. Determine flow rate, approach velocity, and energy dissipation for dam spillway design.
Evapotranspiration Calculator
Estimate reference evapotranspiration (ET₀) using a simplified Penman-Monteith approach from temperature, humidity, wind speed, and solar radiation.
Flood Frequency Analysis
Estimate the design flood discharge for a given return period using a simplified log-Pearson Type III frequency analysis.
Groundwater Recharge
Estimate annual groundwater recharge from precipitation, runoff coefficient, and evapotranspiration using the water balance method.
Rational Method Runoff
Calculate peak stormwater discharge using the Rational Method (Q = CIA/360). Estimate runoff from rainfall intensity, runoff coefficient, and catchment area.
SCS Curve Number
Calculate runoff depth using the USDA SCS (NRCS) Curve Number method. Determine runoff, infiltration, and initial abstraction from precipitation and curve number.
Stream Flow Calculator
Calculate stream discharge from average velocity, channel width, and depth. Includes Froude number, hydraulic radius, and flow regime classification.
Unit Hydrograph Calculator
Calculate the SCS triangular unit hydrograph peak flow, time to peak, and time base from drainage area, lag time, and storm duration.
Water Budget Calculator
Calculate the water balance for a watershed or region. Determine storage change from precipitation, evapotranspiration, runoff, and groundwater outflow.
Watershed Area Calculator
Calculate drainage area and morphometric parameters of a watershed from perimeter, shape factor, and longest flow path.
Ecology & Conservation
Population estimates, habitat area, biodiversity indices and wildlife management.
Carbon Flux Calculator
Calculate Net Ecosystem Exchange (NEE) from gross primary production and ecosystem respiration. Determine if an ecosystem is a carbon sink or source.
Habitat Suitability Score Calculator
Calculate a Habitat Suitability Index (HSI) from food, water, cover, and disturbance scores using the geometric mean method.
Home Range Calculator
Estimate animal home range area using a simplified Minimum Convex Polygon (MCP) method from maximum observed distance.
Invasive Species Impact Calculator
Project invasive species population growth and spatial spread over time. Estimate area occupied and time to full invasion.
Island Biogeography Calculator
Predict species richness from island area and distance using the species-area relationship (S = cA^z) from MacArthur & Wilson's theory.
Mark-Recapture Population Estimator
Estimate wild population size using the Lincoln-Petersen mark-recapture method with Chapman correction and confidence intervals.
Population Growth Calculator
Model logistic and exponential population growth over time using initial population, growth rate, and carrying capacity.
Species Diversity Index Calculator
Calculate Shannon-Wiener (H'), Simpson's Diversity Index, and evenness from species abundance data for up to 10 species.
Trophic Level Energy Calculator
Calculate energy transfer through trophic levels. See how energy diminishes from producers to top consumers based on ecological efficiency.
Water Quality Index (WQI) Calculator
Calculate a composite Water Quality Index (0-100) from dissolved oxygen, pH, BOD, nitrate, phosphate, turbidity, and temperature change.
Biodiversity Index Calculator
Calculate Shannon-Wiener, Simpson's, and Margalef biodiversity indices from species count data for conservation assessment.
Carbon Credit Calculator
Estimate verified carbon credits generated from conservation projects based on project type, area, and verification standard.
Coral Reef Restoration Cost Calculator
Estimate per-hectare costs for coral reef restoration using gardening, larval seeding, or substrate deployment methods.
Ecosystem Services Value Calculator
Estimate the annual dollar value of ecosystem services including water filtration, pollination, carbon sequestration, and flood control.
Endangered Species Recovery Calculator
Model population growth from breeding program parameters to predict recovery timeline and genetic diversity retention.
Invasive Species Removal Cost Calculator
Estimate treatment cost per acre for invasive species removal by species type and method, including retreatment and monitoring.
Land Conservation Value Calculator
Calculate conservation easement value based on development rights forgone and estimate federal and state tax benefits.
Reforestation Cost Calculator
Estimate per-acre costs for tree planting projects including seedlings, site preparation, labor, and maintenance.
Wetland Restoration Calculator
Estimate wetland restoration costs and ecological benefits including water filtration, carbon sequestration, and flood control.
Wildlife Passage Design Calculator
Calculate underpass or overpass dimensions for target wildlife crossing species, including openness ratio and cost estimation.
Bird Count Estimator
Estimate bird population size from point count survey data with distance-based detection correction and confidence intervals.
Deer Density Calculator
Calculate deer density per square mile from observation data, detection rates, and harvest records to assess population status.
Fish Stocking Rate Calculator
Calculate optimal fish stocking density for sport fisheries management based on water body characteristics, species, and management goals.
Habitat Corridor Design Calculator
Determine minimum corridor width and dimensions for wildlife movement based on target species home range and movement needs.
Habitat Quality Index Calculator
Assess habitat quality using a multi-factor scoring system based on vegetation, water, food, structure, and disturbance levels.
Hunting Season Calculator
Estimate recommended season length, bag limits, and sustainable harvest numbers based on species population data and management goals.
Migration Pattern Calculator
Predict flyway timing, stopover duration, and migration windows for migratory bird species based on location, season, and species group.
Population Viability Analysis Calculator
Estimate extinction probability from population size and environmental/demographic variability using diffusion approximation models.
Trophy Score Calculator
Calculate Boone & Crockett and Pope & Young scoring for deer, elk, and moose antlers based on standard measurements.
Wildlife Camera Trap Spacing Calculator
Calculate optimal camera trap density and spacing for wildlife population estimation surveys based on species home range and detection probability.
Waste & Remediation
Diversion rates, landfill volume, contaminated soil quantities and cleanup cost.
Composting Facility Sizing Calculator
Size windrow or vessel composting facilities from feedstock volume, type, and processing method.
Construction Waste Calculator
Estimate demolition debris volume and material-specific recycling rates for construction and demolition projects.
E-Waste Recovery Value Calculator
Calculate recoverable material value from electronic waste streams including precious metals, copper, and refurbishment potential.
Hazardous Waste Manifest Calculator
Track hazardous waste quantities for RCRA manifest compliance, estimate disposal costs, and determine generator category.
Landfill Life Calculator
Estimate remaining landfill capacity and closure date from current intake rate, compaction, and diversion.
Recycling Rate Calculator
Calculate waste diversion rate from stream-by-stream composition data including recycling and composting.
Transfer Station Throughput Calculator
Calculate vehicle count, tipping floor needs, and compactor capacity for daily waste transfer station operations.
Waste Generation Calculator
Estimate daily municipal solid waste volume from population and per-capita generation rates with future projections.
Waste-to-Energy Output Calculator
Calculate energy generation from waste combustion based on waste composition, moisture content, and plant efficiency.
Zero Waste Audit Calculator
Score your waste diversion program and identify opportunities to improve recycling, composting, and reuse toward zero waste goals.
Soil Remediation Cost Calculator
Estimate soil excavation and disposal costs by contaminant type, volume, and disposal method.
Groundwater Treatment Calculator
Size a pump-and-treat system from plume dimensions, aquifer properties, and cleanup targets.
Vapor Intrusion Assessment Calculator
Evaluate the vapor intrusion pathway using Johnson-Ettinger model attenuation factors and EPA screening levels.
In-Situ Treatment Calculator
Calculate injection well spacing, reagent volumes, and costs for in-situ chemical oxidation or reduction.
Monitored Natural Attenuation Calculator
Estimate MNA cleanup timeline from contaminant half-life and monitoring network costs.
Soil Vapor Extraction Calculator
Size an SVE system: extraction well spacing, airflow rates, and blower sizing for VOC removal.
Bioremediation Calculator
Calculate nutrient dosing for enhanced bioremediation using the C:N:P ratio of 100:10:1.
Risk-Based Screening Level Calculator
Calculate risk-based soil and groundwater screening levels using EPA RSL methodology.
Cap Design Calculator
Design multi-layer engineered caps for contaminated sites per EPA/RCRA guidance.
Remediation Timeline Calculator
Estimate total project duration from investigation through regulatory closeout by remediation technology.
Solar Panel Savings Calculator
Calculate solar panel savings, payback period, and return on investment. Includes federal tax credits, production estimates, and 25-year projections.
Electricity Cost Calculator
Calculate the electricity cost of any appliance or device. Find out daily, monthly, and yearly energy costs based on wattage and usage.
Water Usage Calculator
Estimate your daily, monthly, and annual water usage and cost. Identify which activities use the most water.
EV Savings Calculator
Calculate how much you'd save by switching to an electric vehicle, including fuel, maintenance, and CO2 reduction.
Home Energy Audit Calculator
Evaluate your home's energy efficiency and find potential savings from upgrades like better windows and insulation.
Tree Planting Impact Calculator
Calculate the environmental impact of planting trees. See CO2 absorbed, oxygen produced, and the equivalent in cars offset or miles driven.
Recycling Impact Calculator
Calculate the environmental impact of recycling. See how much CO2, energy, and water you save by recycling.
Compost Calculator
Calculate how much compost you can produce and its environmental impact. Track your composting efforts.
Carbon Footprint Master Calculator
Complete carbon footprint calculator — estimate your total emissions, analyze commute impact, compare EV vs gas vehicles, and calculate carbon offset costs.
Carbon Footprint Calculator
Estimate your annual carbon footprint from driving, electricity, heating, and air travel. Compare to US and world averages.
Carbon Offset Calculator
Calculate carbon emissions from flights, driving, or electricity use. See how many trees needed to offset and estimated offset cost.
Commute Emissions Calculator
Calculate the annual carbon emissions and fuel cost from your daily commute. Compare car, hybrid, EV, bus, and bike options.
Phase I ESA Cost Calculator
Estimate Phase I Environmental Site Assessment costs based on property type, acreage, building count, historical use complexity, and geographic region per ASTM E1527-21.
Remediation Cost Estimator Calculator
Estimate contaminated site cleanup costs by contaminant type, remediation method, soil volume, depth, and groundwater impact.
Air Quality Permit Cost Calculator
Estimate air quality permit application costs for minor source, Title V, and PSD/NSR permits including modeling, BACT analysis, and compliance.
Wetland Delineation Cost Calculator
Estimate jurisdictional wetland delineation costs based on site acreage, terrain, wetland types, and USACE jurisdictional determination needs.
EIS Cost Estimator Calculator
Estimate Environmental Impact Statement costs under NEPA based on project scale, resource areas, alternatives, public controversy, and agency review cycles.
Stormwater Permit Compliance Calculator
Estimate NPDES stormwater permit compliance costs including SWPPP preparation, BMP installation, post-construction management, and ongoing monitoring.
Brownfield Redevelopment Calculator
Analyze brownfield redevelopment feasibility by comparing cleanup costs, incentives, development costs, and projected property value gains.
Noise Impact Assessment Calculator
Calculate received noise levels at a receptor from a point source accounting for distance, atmospheric absorption, ground effects, and barriers per ISO 9613-2.
Endangered Species Survey Cost Calculator
Estimate biological survey costs for endangered/threatened species by habitat type, target taxa, species count, and seasonal survey requirements under ESA.
Carbon Offset Project ROI Calculator
Evaluate carbon offset project financial returns based on project type, credit generation, market pricing, and verification costs under voluntary or compliance registries.