Calculate what fraction of the reactant molar mass ends up in the desired product.
| Atom economy (%) | – |
Use this calculator for green-chemistry write-ups when you know the formula weights from the balanced equation and want atom-economy percent before discussing E-factor.
Atom economy = (MW of desired product ÷ sum of reactant MWs) × 100. Use the balanced equation’s formula weights multiplied by their coefficients, not the grams you actually weighed. This is a theoretical atom-efficiency number; it does not include yield, solvents, or work-up.
Desired product MW × coeff.: Molar mass of the product you keep, in g/mol, multiplied by its stoichiometric coefficient.
Sum of reactant MW × coeff.: Sum of molar masses of all reactants in the balanced equation, each multiplied by its coefficient, in the same units.
Atom economy (%): Percent of reactant formula weight that appears in the desired product.
Related calculators