The theoretical yield of a reaction is the amount of product that would be produced in a complete reaction. Theoretical yield is based on ideal conditions and can be calculated through stoichiometry – a calculation of relative reactants and products in a reaction.
In analyzing the results of an experiment, the experimenter must run the actual yield against the theoretical yield to find the percent yield. Divide the actual yield by the theoretical yield and multiply the decimal answer by 100 to find a percentage. The percent yield helps to measure the success of lab conditions for the experiment and can tell the experimenter whether he should run more trial experiments.