Percent Yield Calculator
Enter the actual yield and the theoretical yield.
This result is an estimate only. Double-check important figures before relying on them.
How it is calculated
- Percent yield = actual yield ÷ theoretical yield × 100
- Difference = theoretical yield − actual yield
To convert masses to moles first, use the mole calculator.
Worked example
You collect 8 g where the theoretical yield is 10 g:
- Percent yield = 80%
- Difference = 2 g
Why your number may differ
Both yields must be in the same unit. The theoretical yield must come from the limiting reactant of the balanced equation.
Frequently asked questions
What is percent yield?
The actual amount of product you collect divided by the theoretical maximum, times 100.
Why is it usually below 100%?
Reactions may be incomplete, products can be lost during transfer or purification, and side reactions use up reactants.
Can it be over 100%?
Not in theory. A result over 100% usually means the product is impure or still wet.