Percent Yield Calculator
Percent yield from the actual and theoretical yield, either yield from the other and a percentage, or the theoretical yield from the limiting reactant and the balanced equation.
Result
Percent yield: 77.2871%
Uses your molar masses and equation. For hazards and handling, see the substances’ safety data sheets.
- Actual yield
- 0.392 g (0.000392 kg)
- Theoretical yield
- 0.5072 g (0.000507 kg)
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How to use the Percent Yield Calculator
- Choose what to find, the percent yield, the actual or theoretical yield, or the theoretical yield from the limiting reactant.
- Enter the masses in grams or kilograms, and for the reactant route the molar masses and the balanced equation's coefficients.
- Read the percent yield with the actual and theoretical yields beside it.
The formulas
percent yield = actual yield ÷ theoretical yield × 100%actual yield = theoretical yield × percent yieldtheoretical yield = actual yield ÷ percent yieldfrom the limiting reactant, for a Reactant → b Product:moles of reactant = mass ÷ molar mass of the reactantmoles of product = moles of reactant × b ÷ atheoretical yield = moles of product × molar mass of the productAssumptions
The reactant entered is the limiting one: the reactant that runs out first. If you are not sure, work out the moles of product each reactant could make and use the smallest. The molar masses are yours to enter; the molar mass calculator on this site works them out from a formula.
With your numbers
- Percent yield = 0.392 g ÷ 0.5072 g × 100% = 77.2871%
Quick reference
Uses your molar masses and equation. For hazards and handling, see the substances’ safety data sheets.
| Example | Result |
|---|---|
| 0.392 g of a theoretical 0.5072 g | Percent yield: 77.2871% |
| 1.1 g of a theoretical 1.0 g | Percent yield: 110% |
| 80% of a theoretical 2.5 g | Actual yield: 2 g |
| Theoretical yield for 1.6 g at 80% | Theoretical yield: 2 g |
| 1.274 g at 159.61 g/mol, 1 to 1, to 63.55 g/mol | Theoretical yield: 0.507253 g |
| 10 g at 50 g/mol, 2 to 1, to 80 g/mol | Theoretical yield: 8 g |
Common questions about the Percent Yield Calculator
- How do I calculate percent yield?
- Divide the mass of product you actually collected by the theoretical yield, the most the reaction could make, and multiply by 100%. Collecting 0.392 g of copper when the theoretical yield is 0.5072 g is a percent yield of about 77.3%.
- How do I find the theoretical yield?
- Convert the limiting reactant to moles by dividing its mass by its molar mass, scale by the balanced equation's mole ratio of product to reactant, and multiply by the product's molar mass. For 1.274 g of copper sulfate at 159.61 g/mol reacting 1 to 1 to copper at 63.55 g/mol, that is about 0.507 g.
- Why is my yield below 100%?
- Some product is always lost: left on glassware, dissolved in the filtrate, or lost to side reactions and reactions that do not go to completion. A yield well below what the method usually gives is worth checking against each step.
- Can percent yield be over 100%?
- Not for pure, dry product. A figure above 100% nearly always means the weighed product still holds water or solvent, carries impurities, or a mass was misread. The page computes the figure and adds a note rather than refusing it.