Theoretical Yield Calculator
Calculate the maximum product mass from a known limiting reactant and a balanced molar ratio.
01 Set up your calculation
- Identify the limiting reactant using all starting quantities.
- Enter its mass and molar mass, then both coefficients from the balanced equation.
- Enter the product molar mass and read the theoretical product quantity.
02 The relationship
For the assumptions behind these results, read the explanation below. You can also explore Molar Ratio and Percent Yield.
Follow the numbers
For 10 g of a limiting reactant with molar mass 100 g/mol, a 1:2 reactant-to-product ratio produces 0.2 mol of product. At 25 g/mol, the theoretical yield is 5 g.
03 Work through mass, moles, and mass again
The calculation first converts the available limiting-reactant mass into moles. The balanced coefficients then convert reactant moles into product moles. Finally, multiplying by the product’s molar mass gives the maximum product mass.
The reactant and product molar masses are separate properties. Reusing the reactant’s molar mass for the product is only correct if they happen to have the same value.
04 The limiting reactant must be established first
This tool assumes that the entered reactant is limiting and that the other required reactants are available in sufficient amounts. If you are uncertain, calculate the possible product amount from each reactant; the smallest available amount controls the theoretical yield.
The result assumes the stated reaction goes to completion without competing processes. Use measured or expected percentage yield separately to estimate an actual recovered quantity. Theoretical yield is a stoichiometric bound, not a promise about a laboratory experiment.
Questions from the notebook
Does this choose the limiting reactant?
No. Supply the reagent already identified as limiting, or compare calculations from each reactant.
Can the product mass exceed the entered reactant mass?
Yes. Atoms from other reactants can contribute to the product mass.
Can I use a hydrated product?
Yes, when its molar mass and reaction stoichiometry refer consistently to that hydrate.
References & reading
- OpenStax, Rice University — Reaction Yields ↗
Defines actual, theoretical, and percentage yield and explains limiting-reactant calculations.
- OpenStax, Rice University — Reaction Stoichiometry ↗
Derives mole relationships from balanced reaction coefficients and converts between moles and mass.
- NIST — Guide to SI conversion factors ↗
Supports physical unit conversions. Input values are converted to the formula’s base units before calculation.
Our explanations are written for ChemistryCalc. Read how we build and check our tools. These calculations are educational estimates where the underlying model requires assumptions.