Reacting Mass Calculator
A free teacher tool that makes reacting-mass and limiting-reactant calculations transparent by showing the balanced equation, moles, equation ratio and calculated mass.
What the calculator does
- Uses a balanced chemical equation as the starting point.
- Converts the supplied masses into amounts in moles.
- Applies the stoichiometric ratio from the equation.
- Identifies the limiting reactant when two masses are supplied.
- Displays each stage so the reasoning can be checked and explained.
The calculation route
mass → moles → mole ratio → moles → mass
The mole is at the heart of the calculation. A mass of one substance cannot be converted directly into the mass of another.
Open the calculator
Select an example or enter a balanced equation and the available masses.
Launch Reacting Mass CalculatorThe calculator opens in a new browser tab.
Using the Reacting Mass Calculator
The short demonstration below uses the thermite reaction to show how the calculator identifies the limiting reactant and determines the mass of iron produced.