Science

Percent Yield Calculator

Actual vs theoretical reaction yield.

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Results
Percent yield
82.69%
Mass lost
1.8 g
Percent lost
17.31%
Quality
Good

Quick answer

Percent yield is actual yield divided by theoretical yield times 100; above 100% signals impurity or error.

% yield = Actual ÷ Theoretical × 100

How to use the Percent Yield Calculator

  1. 1Weigh the purified product you obtained.
  2. 2Calculate theoretical yield from stoichiometry.
  3. 3Enter both masses in the same unit.

Frequently asked questions

Can yield exceed 100%?

Only if the product is wet or contaminated — dry and reweigh.

What is a normal yield?

70–90% for a well-run synthesis; multi-step routes are much lower.