Percent Yield Calculator

This calculator finds the percent yield of a chemical reaction, the standard measure of how efficient a reaction was, from the actual yield and the theoretical yield. In chemistry, the theoretical yield is the maximum amount of product a reaction could possibly make, calculated from the balanced equation and the limiting reactant, assuming everything reacts perfectly. The actual yield is what you really obtain in the laboratory, which is almost always less, because reactions can be incomplete, side reactions occur, and product is lost during transfer, filtration and purification. The percent yield compares the two: it is the actual yield divided by the theoretical yield, expressed as a percentage. It tells you what fraction of the possible product you actually captured, and it is a key figure in every chemistry course and in industrial process chemistry, where a few percent of yield can mean a great deal of money. This tool makes the calculation instant. You enter the actual yield you obtained and the theoretical yield you calculated, in the same units, usually grams or moles, and it returns the percent yield. It also shows the shortfall, the amount of product lost compared with the theoretical maximum, so you can see how much was not recovered. The results update as you type. Use it for chemistry homework and laboratory reports, or to assess how well a synthesis or process performed. A note on interpretation: a percent yield above one hundred usually signals an error or impurity, such as leftover solvent or water making the product seem heavier than it should, rather than a genuinely impossible result. The calculation is rounded for display.

Percent yield = (actual / theoretical) x 100. Use the same units for both. A result above 100% usually indicates impurity or error. Rounded for display.