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Atom Economy Calculator

How much reactant mass can reach the product at all.

Work out Atom Economy. How much reactant mass can reach the product at all. Names the convention that makes the answer wrong.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these
g/mol
g/mol
g/mol
g/mol

Atom economy

72.73%

30 g/mol leaves as by-product

Atom economy72.727%
Total reactant mass110 g/mol
Mass in the product80 g/mol
Mass wasted30 g/mol

Atom economy is a property of the equation, not of the run: it asks what share of the reactant mass could end up in the product even if everything went perfectly. A reaction can have a 100% yield and a 40% atom economy, which is why green chemistry treats the two as separate measures. Addition reactions score highest because nothing is expelled; substitutions and eliminations always discard something.

How the Atom Economy Calculator works

Atom economy is a property of the equation rather than of the run: it asks what share of reactant mass could end up in the product even if everything went perfectly. A reaction can have a 100% yield and a 40% atom economy.

Also known as: percentage atom economy · green chemistry metric calculator · atom economy formula · how to calculate atom economy

Frequently asked questions

How do I calculate atom economy?

Divide the molar mass of the desired product by the total molar mass of all reactants, weighted by their coefficients, and multiply by 100.

How is it different from yield?

Yield measures how much of the possible product you actually got. Atom economy measures how much of the input mass the equation allows to reach the product at all. They are independent, and green chemistry tracks both.

Which reactions score best?

Addition reactions, where nothing is expelled, can reach 100%. Substitutions and eliminations always discard something and cannot.

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The one-line version
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