About the Mole Ratio Calculator
Mole ratio between any two species in a balanced equation, and the moles produced from a given amount.
Also known as: stoichiometric ratio, molar ratio, coefficient ratio.
How to use this calculator
- Enter chemical equation, from compound, to compound, moles available.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
ratio = coefficient of product ÷ coefficient of reactant
Worked example
Using the values pre-filled in the calculator above:
- Chemical equation: 2H2 + O2 -> 2H2O
- From compound: H2
- To compound: H2O
- Moles available = 4 mol
the calculator returns:
- Mole ratio: 2 H2 : 2 H2O
- Ratio as a number: 1
- Moles of H2O: 4 mol
- Mass of H2O: 72.06 g