Limiting Reactant Calculator
Compare available reaction units for two reactants.
Limiting Reactant measurements
Enter your values, then calculate.
Result
How to calculate limiting reactant
This calculator identifies the limiting reactant in a chemical reaction — the reactant that runs out first and determines how much product can form.
How the calculation works
Limiting reactant indicator = min(Moles of A ÷ Coefficient of A, Moles of B ÷ Coefficient of B). The smaller value identifies which reactant limits the reaction.
Example
3 moles of A (coefficient 1) and 4 moles of B (coefficient 2): min(3÷1, 4÷2) = min(3, 2) = 2, meaning B is the limiting reactant.
Frequently asked questions
How is Result calculated?
Result = min([Moles of A] ÷ [Coefficient of A], [Moles of B] ÷ [Coefficient of B]).
Is the Limiting Reactant Calculator free to use?
Yes — every calculator on Simple Calculator Tools is free, runs in your browser, and does not require an account.
Limiting Reactant Calculator
Limiting reactant indicator = min(Moles of A ÷ Coefficient of A, Moles of B ÷ Coefficient of B). The smaller value identifies which reactant limits the reaction.
Let's understand your limiting reactant result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Limiting Reactant
- Divide each reactant's moles by its stoichiometric coefficient from the balanced equation — the smaller result identifies the limiting reactant.
- The limiting reactant determines the maximum theoretical yield of product; any excess of the other reactant remains unreacted.
Common Limiting Reactant Mistakes to Avoid
- Comparing raw mole amounts directly without dividing by each reactant's stoichiometric coefficient, which can identify the wrong reactant as limiting.
When to Use This Calculator
This calculator identifies the limiting reactant in a chemical reaction — the reactant that runs out first and determines how much product can form.