Actual Yield Calculator — Percent Yield Chemistry
Find the percent yield of a chemical reaction: enter the actual yield (mass of product collected) and the theoretical yield (maximum mass from stoichiometry), and get the efficiency of your reaction instantly.
g
g
Fraction of the theoretical maximum actually obtained
- 1
Actual ÷ theoretical yield
4.2 ÷ 5 = 0.84Fractional yield before converting to a percentage. - 2
Percent yield × 100
0.84 × 100 = 84 %
How does this calculator work?
Percent yield = (actual yield ÷ theoretical yield) × 100. Both masses must be in the same unit (grams). The theoretical yield comes from stoichiometry and the limiting reagent; the actual yield is what you collect. A 100 % yield is the physical maximum — real reactions are always lower due to losses and incomplete conversion.
Formula
How this is calculated
In any chemical reaction, stoichiometry sets an upper limit — the theoretical yield — on how much product can form if the reaction goes to 100 % completion with no losses. In practice, reactions rarely go to completion; side reactions occur, the product is lost during filtration or transfer, and small amounts remain in solution. The actual yield is what you physically collect and weigh.
Percent yield = (actual yield ÷ theoretical yield) × 100 expresses the efficiency of the process. A 100 % yield is the theoretical maximum and essentially never achieved in a real lab; 70–90 % is good for a well-optimised synthesis, and many complex multi-step reactions reach only 30–50 % per step. Industrial processes often target high percent yield to minimise raw-material waste and cost.
Both yields must be in the same mass units (grams here). The theoretical yield is computed from the balanced equation and the limiting reagent: use molar mass and stoichiometric coefficients to convert the limiting reagent mass to the expected product mass before entering it here. The actual yield must never exceed the theoretical yield — if it does, the measurement, units, or stoichiometric calculation contains an error.
Frequently asked questions
Balance the reaction equation, identify the limiting reagent (the one that runs out first), convert its mass to moles using its molar mass, use the stoichiometric ratio to get moles of product, then multiply by the product's molar mass. That final value is the theoretical yield in grams.
A percent yield above 100 % is physically impossible — it means either the actual yield measurement is wrong (impure product, incomplete drying, weighing error) or the theoretical yield calculation has an error. Check your molar masses, stoichiometric coefficients, and the limiting-reagent identification.
It depends on the reaction. For a simple precipitation or neutralisation, 90–99 % is achievable. A multi-step organic synthesis might give 60–80 % per step, and the cumulative yield of 5 steps at 80 % each is only about 33 %. Industrial processes are optimised to push yields as high as economically practical.
Also known as
TG we-Calculate Editorial Team. (2026). Actual Yield Calculator — Percent Yield Chemistry [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/actual-yield-calculator
TG we-Calculate Editorial Team. "Actual Yield Calculator — Percent Yield Chemistry." TG we-Calculate. 2026. https://we-calculate.com/calculator/actual-yield-calculator.
TG we-Calculate Editorial Team, "Actual Yield Calculator — Percent Yield Chemistry," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/actual-yield-calculator
@misc{wecalculate_actual_yield_calculator, title = {Actual Yield Calculator — Percent Yield Chemistry}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/actual-yield-calculator}}, year = {2026}, note = {TG we-Calculate} }
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