Percent Yield Calculator
Compare the actual yield of a reaction with the theoretical yield.
About the Percent Yield Calculator
Enter the mass of product you actually obtained and the theoretical yield, in the same unit. The calculator gives the percent yield and how much was lost.
Theoretical yield is the product you'd get if the limiting reagent reacted completely, worked out from the balanced equation and molar masses. Percent yield shows how efficient the real reaction was.
The formula
Percent yield = actual ÷ theoretical × 100
Worked example
8.2 g of product from a theoretical 10 g
- 8.2 ÷ 10 × 100 = 82%
- 18% was lost
Things to keep in mind
- Both yields must be in the same unit (grams or moles).
Questions people ask
How do I find theoretical yield?
Moles of limiting reagent × mole ratio × product molar mass.
Why is yield below 100%?
Side reactions, equilibrium, losses in transfer and purification.