Theoretical, experimental and percentage yield
The theoretical yield of a reaction is the amount of product you would get if you use up all of the limiting reagent, and if there is no loss, e.g. by degradation of reactant or product or by formation of byproducts. The experimental yield is the actual amount of product you obtain when performing a given experiment. The percentage yield is a calculation of how large a percentage of the theoretical yield you obtained in a given experiment. It is calculated by:
In most cases, when the yield of a reaction is mentioned without referring to either theoretical, experimental or percentage yield, it is implicitly the percentage yield that is meant.