Percent Yield Calculator

To find the actual yield, rearrange the standard formula by multiplying your theoretical yield by the percent yield, and then divide that product by 100. For instance, if your theoretical yield is 50 grams and your percent yield is 80%, your actual yield equals 50 multiplied by 0.80, which gives you 40 grams of recovered product.

Yes, a percent yield can mathematically exceed 100%, but it does not mean your reaction defied the laws of conservation of mass. Instead, an experimental yield over 100% almost always indicates that your isolated product is contaminated with unreacted starting materials, leftover drying agents, or trapped solvent that adds unwanted extra weight to your final measurement.

Theoretical yield is the maximum possible amount of product that could be formed in a chemical reaction, calculated purely through paper-and-pencil stoichiometry assuming absolute perfection. Actual yield, on the other hand, is the physical, measured mass of product you successfully isolate at the end of a real laboratory experiment, which is almost always lower due to side reactions or product loss during transfer.

While a 100% percent yield is theoretically possible on paper, it is extremely rare in real-world practical chemistry. Most laboratory procedures suffer from incomplete reactions, side reactions, or mechanical loss of product during filtration and extraction phases, meaning actual yields generally fall somewhere between 70% and 95% under good conditions.