When to use this calculator
Compare actual product yield with theoretical yield. An apparent yield above 100% can indicate impurities, retained solvent or measurement problems.
Explore the reaction quantities & yield calculators for other questions in this topic. For a related calculation, use the Reaction Conversion Calculator: Find the consumed fraction of an initially supplied reactant.
PUTTING IT INTO PRACTICE
Percent 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 |
|---|---|
| Actual yield (g) | 8 |
| Theoretical yield (g) | 10 |
| Result | 80 % |
- Check the input labels and enter the example values above.
- Apply the relationship: Percent yield = actual ÷ theoretical × 100.
- The result is 80 %, rounded for display.
How to interpret your result
An apparent yield above 100% can indicate impurities, retained solvent or measurement problems.
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.
How do I use the percent yield calculator?
Enter actual yield (g), theoretical yield (g). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Percent yield = actual ÷ theoretical × 100.
What should I check before using the result?
An apparent yield above 100% can indicate impurities, retained solvent or measurement problems.
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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