Atom Economy Calculator

01 Set up your calculation

1. Balance the reaction and identify the desired product.
2. Enter all consumed reactants’ molar masses and their matching coefficients.
3. Enter the desired product’s molar mass and coefficient. Exclude catalysts and solvents that are not consumed.

02 The relationship

For the assumptions behind these results, read the explanation below. You can also explore Percent Yield and Molar Mass.

03 Start with a balanced equation

Coefficients specify how many moles of each substance participate in the chosen reaction basis. Multiplying a molar mass by its coefficient places every substance on that same basis. Scaling all coefficients equally leaves atom economy unchanged.

Include every stoichiometrically consumed reactant, even when it is inexpensive or commonly described as a reagent. Omitting one can produce an inflated percentage or an impossible result above 100%.

04 Distinguish atom economy from yield

Atom economy describes the reaction pathway’s theoretical allocation of atoms. It does not use the mass actually isolated in a laboratory. A reaction can have excellent atom economy and a poor experimental yield.

It also does not capture solvent use, heating, toxicity, purification losses or excess reagent. Use it as one measure when comparing chemical routes, alongside the practical factors the calculation leaves out.