Calculate reaction efficiency from actual and theoretical yields — or solve for any variable.
Enter any two values and the third is calculated instantly. "Actual yield" is the mass of product you actually isolated. "Theoretical yield" is the maximum possible product calculated from stoichiometry (use our Theoretical Yield Calculator to find this). Percent yield tells you how efficient your reaction was.
% Yield = (Actual Yield / Theoretical Yield) × 100
Worked example: You calculated a theoretical yield of 5.0 g for an ester synthesis. After running the reaction, workup, and purification, you isolated 3.2 g of product. % Yield = (3.2 / 5.0) × 100 = 64%.
A yield above 100% usually indicates impurities (residual solvent, unreacted starting material, or byproducts co-purifying with your product), not a miraculous reaction. Typical yields vary widely by reaction type: simple precipitations and crystallizations often achieve 80–95%, while multi-step organic syntheses might give 30–70% per step. Total synthesis yields compound multiplicatively — five steps at 80% each gives only 33% overall.