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Percent yield calculator

Actual over theoretical, as a percentage. Leave the unknown blank.

Work it out

%

Fill in all but one. 3 boxes are empty, so there is more than one answer.

A worked example

A reaction could give 4.50 g of ester and gives 3.72 g after work-up.

82.7%

  1. 1(3.72 / 4.50) × 100 = 82.7%.
  2. 2The missing 17.3% is loss on work-up, incomplete conversion, or side products — the number alone does not say which.

What this assumes

  • The theoretical yield must come from the limiting reagent. Using the reagent in excess gives a theoretical yield that is too high and a percent yield that is wrongly low.

The terms used here

Theoretical yield
The mass of product if every molecule of the limiting reagent became product.
Actual yield
What you isolated and weighed, after work-up and purification.

This calculator runs in your browser. Nothing you type is sent anywhere, and no account is needed. If you want to go further than arithmetic — look a structure up, see what a reaction has been recorded as giving, or follow a mechanism — the library is open too.