When to use this calculator
Balance the reaction first to determine the product-to-reactant mole ratio. A mass ratio cannot substitute for this molar ratio.
Explore the reaction quantities & yield calculators for other questions in this topic. For a related calculation, use the Dilution Calculator: Find stock volume required for a target diluted concentration.
PUTTING IT INTO PRACTICE
Theoretical Yield: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Reactant mass (g) | 10 |
| Reactant molar mass (g/mol) | 20 |
| Product moles per reactant mole | 2 |
| Product molar mass (g/mol) | 30 |
| Result | 30 g |
- Check the input labels and enter the example values above.
- Apply the relationship: Product mass = reactant mass/reactant molar mass × mole ratio × product molar mass.
- The result is 30 g, rounded for display.
How to interpret your result
Assumes the entered reactant is limiting and reaction completion is ideal.
Balance the chemical equation before using mole ratios. Identify the limiting reactant separately. Yield, purity and atom economy measure different aspects of a reaction and should not be substituted for one another.
Frequently asked questions
Is percent yield the same as atom economy?
No. Yield compares actual product against a theoretical amount; atom economy describes stoichiometric use of reactant mass in the desired product.
When is the theoretical yield calculator useful?
Balance the reaction first to determine the product-to-reactant mole ratio. A mass ratio cannot substitute for this molar ratio.
How do I use the theoretical yield calculator?
Enter reactant mass (g), reactant molar mass (g/mol), product moles per reactant mole, product molar mass (g/mol). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Product mass = reactant mass/reactant molar mass × mole ratio × product molar mass.
What should I check before using the result?
Assumes the entered reactant is limiting and reaction completion is ideal.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Further reading
For background on this topic, see OpenStax: quantitative chemical analysis ↗. This is a topic reference, not an external review or endorsement of this tool.
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