Skip to main content
Calcimator

Stoichiometry Calculator

Calculate product mass from reactant mass using molecular weights and mole ratios. Supports percent yield for practical lab calculations.

Inputs

g
g/mol
g/mol

Results

Theoretical Product Mass

146.1 g

Percent Yield

0%

Reactant Moles2.5 mol
Product Moles2.5 mol
How to Use This Calculator
  1. Enter reactant mass (g), reactant molecular weight (g/mol), and product molecular weight (g/mol).
  2. Set the mole ratio (product:reactant) from your balanced equation.
  3. Optionally enter actual yield to calculate percent yield.
  4. Review Theoretical Product Mass (g), Reactant Moles, and Percent Yield if actual yield is provided.

How the result changes with Reactant Molecular Weight

Reactant Molecular WeightTheoretical Product MassPercent Yield
10,0000.584 g0%
35,0000.167 g0%
65,0000.09 g0%
90,0000.065 g0%

What each input means

Reactant Mass
Mass of the starting reactant in grams
Reactant Molecular Weight
Molar mass of the reactant (e.g., NaOH = 40 g/mol)
Product Molecular Weight
Molar mass of the desired product (e.g., NaCl = 58.44 g/mol)
Mole Ratio (Product:Reactant)
Stoichiometric coefficient ratio of product to reactant from balanced equation
Actual Yield (optional)
Actual mass of product obtained — leave 0 to skip percent yield calculation

How this is calculated

Formula

product mass = (reactant mass / reactant MW) × mole ratio × product MW

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Reactant Mass = 100, Reactant Molecular Weight = 40, Product Molecular Weight = 58.44, Mole Ratio (Product:Reactant) = 1 = 5 input(s) provided
  2. Calculate Theoretical Product Mass
    Theoretical Product Mass = pm
    146.1 = 146.1
  3. Calculate Percent Yield
    Percent Yield
    0 = 0%
  4. Calculate Reactant Moles
    Reactant Moles
    2.5 = 2.5
  5. Calculate Product Moles
    Product Moles
    2.5 = 2.5

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Chemistry

Empirical Formula Finder

Determine the empirical formula of a compound from elemental percent composition. Supports C, H, O, and N.

Chemistry

Equilibrium Constant Calculator

Calculate the equilibrium constant (Keq) from product and reactant concentrations with stoichiometric coefficients. Includes Gibbs free energy.

Science & Engineering

Chemical Equation Balancer

Balance chemical equations and calculate stoichiometry. Find limiting reactants and product yields.

Dermatology

Melanoma Risk Calculator

Estimate relative melanoma risk based on skin type, mole count, family history, sunburn history, and other established risk factors.

Chemistry

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.

More in Science & Physics.