Percent Yield Calculator
Find the percent yield of a chemical reaction by comparing the mass you actually obtained with the maximum mass predicted by stoichiometry.
g
g
Fraction of the theoretical maximum obtained
- 1
Yield ratio
8.5 ÷ 10 = 0.85 - 2
Percent yield
0.85 × 100 = 85
How does this calculator work?
Percent yield equals the actual yield divided by the theoretical yield, times 100. It shows how much of the maximum possible product you recovered. Enter both masses in grams; values near 100% mean an efficient reaction, while results above 100% point to measurement or calculation errors.
Formula
How this is calculated
Percent yield measures how efficient a reaction was by comparing two masses. The actual yield is the amount of product you really recovered in the lab, while the theoretical yield is the maximum amount predicted from the balanced equation and the limiting reactant. Both should be entered in the same mass unit (grams here) so the ratio is dimensionless.
The calculator divides the actual yield by the theoretical yield and multiplies by 100 to express the result as a percentage. A value near 100% means almost all of the limiting reactant was converted to recovered product; lower values indicate losses from incomplete reaction, side reactions, transfer losses, or impurities removed during purification.
Results above 100% are physically impossible for a pure product and usually signal a measurement or calculation error, such as a wet or impure sample inflating the actual yield, or an underestimated theoretical yield. The theoretical yield must be greater than zero, otherwise the ratio is undefined.
Frequently asked questions
Not for a pure product. A value above 100% normally means the actual yield was measured incorrectly (often because the sample was still wet or contained impurities) or the theoretical yield was miscalculated.
It depends on the reaction. Many synthetic reactions are considered good above 80%, acceptable around 50-80%, and poor below 50%, but ideal benchmarks vary by chemistry and scale.
Identify the limiting reactant, convert its mass to moles, apply the mole ratio from the balanced equation to find moles of product, then convert back to mass using the product molar mass.
Also known as
TG we-Calculate Editorial Team. (2026). Percent Yield Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/percent-yield-calculator
TG we-Calculate Editorial Team. "Percent Yield Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/percent-yield-calculator.
TG we-Calculate Editorial Team, "Percent Yield Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/percent-yield-calculator
@misc{wecalculate_percent_yield_calculator, title = {Percent Yield Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/percent-yield-calculator}}, year = {2026}, note = {TG we-Calculate} }
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