Reaction Yield per Gram Calculator
Gauge how efficiently a reaction turns reactant into product: grams of product per gram of reactant, plus percent yield.
How it works
Yield per gram = actual product ÷ reactant · Percent yield = actual ÷ theoretical × 100
Just as fuel economy measures distance per unit of fuel, this measures product mass per gram of reactant fed in — a quick “mileage” for a reaction. Divide the actual product recovered by the reactant charged for the real figure, and by the theoretical product for the ideal ceiling. Percent yield then compares the actual product to the theoretical amount predicted by stoichiometry; the gap comes from side reactions, incomplete conversion and losses on transfer and purification.
Worked example
Charging 50 g of reactant and recovering 38 g of product gives 38 ÷ 50 = 0.76 g of product per gram of reactant. Against a 45 g theoretical maximum, the percent yield is 38 ÷ 45 × 100 = 84.4%.
Frequently asked questions
How is this different from percent yield?
Percent yield compares what you got to the stoichiometric maximum for that specific reaction. Yield per gram is a plain mass-in to mass-out ratio that lets you compare the productivity of different reactants or routes side by side, independent of molar masses.
Can yield per gram exceed one?
Yes, whenever the product is heavier than the reactant you weighed — for instance when atoms from a second reagent add mass, or when the reactant is the limiting one of several. The value simply reflects grams out per gram of the reactant you tracked.
Why is my percent yield below 100%?
Real reactions lose material to side products, incomplete conversion, and unavoidable handling losses during filtration, washing and drying. A yield above 90% is generally excellent for a multi-step synthesis.
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This calculator is for educational purposes. Double-check important results before acting on them.