Calculate percent, actual, or theoretical yield
A percent yield calculator compares the amount of a product actually obtained with the maximum theoretical amount predicted by stoichiometry. Select which quantity is unknown, enter the other two, and keep actual and theoretical yield in the same unit. The page rearranges one relationship rather than using three unrelated formulas, making reverse checks straightforward.
Mass units such as grams and amount units such as moles can both be used, but the two yield quantities must share the selected basis and describe the same product. Changing a unit label does not perform a mass-to-mole conversion. If one source is in moles and another in grams, convert with the exact product molar mass before calculating yield.
Use the percent yield formulas correctly
Percent yield = actual yield ÷ theoretical yield × 100. Rearranging gives actual yield = theoretical yield × percent ÷ 100 and theoretical yield = actual yield × 100 ÷ percent. Theoretical yield must be positive when it is a denominator, and percent must be greater than zero when solving backward for a theoretical amount.
A zero actual yield produces 0% when theoretical yield is positive. A 100% yield means actual and theoretical amounts are equal. Unlike the simpler actual-yield page, this calculator does not silently cap a calculated percentage at 100. If the measured amount exceeds the theoretical basis, it reports the resulting value and explains why it should trigger investigation.
Follow a percent yield example
Suppose a balanced limiting-reactant calculation predicts 10.0 g product and the isolated dry product weighs 8.40 g. Percent yield = 8.40 ÷ 10.0 × 100 = 84.0%. A reverse calculation multiplies 10.0 g by 84.0/100 and returns 8.40 g, providing a simple check that the percentage was not entered as 84 rather than 0.84 in multiplication.
If 8.40 g represents 70.0%, theoretical yield = 8.40 × 100/70.0 = 12.0 g. Keep extra precision through the division and round according to the measured and theoretical inputs. The number of digits printed by a calculator does not improve balance accuracy, reagent purity, scale calibration, or the assumptions used to identify the limiting reactant.
Investigate an apparent yield above 100 percent
A result above 100% does not demonstrate creation of more pure desired product than stoichiometry permits. Common causes include retained solvent or water, inorganic salts, incomplete drying, side products, contamination, an incorrect tare, scale error, wrong product identity, or an incorrect theoretical-yield calculation. Preserve the anomalous number so the discrepancy remains visible rather than normalizing it away.
Percent yield is also different from conversion, selectivity, purity, atom economy, and recovery at one purification step. A crude mixture may have high measured mass but low purity. A reaction may consume starting material yet form unwanted products. Use analytical identification and a mass balance when the distinction matters, especially in research, regulated work, or expensive production decisions.
Reaction limits, laboratory meaning, and privacy
The calculation does not balance an equation, identify a limiting reactant, calculate theoretical yield from starting materials, or verify product purity. Follow an approved procedure, use appropriate protective equipment, and handle waste correctly for real laboratory work. Yield alone is not a safety metric and cannot reveal thermal hazards, pressure, toxic exposure, or incompatibility.
The values are calculated in the current browser tab. NexaCurrent does not upload the quantities, formulas, chemical names, element choices, or other information entered here, and no account is needed. Copying is a deliberate action after the answer and working are visible. Refreshing or leaving the page clears the current calculation, so keep a copied result if it is needed for later study.