Calculadora de Rendimento Percentual
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
% = (Y_real / Y_teo) × 100
About this calculator
The Percent Yield Calculator is a tool for chemists and students to determine the efficiency of a chemical reaction. It calculates the percent yield by dividing the actual yield (the amount of product obtained experimentally) by the theoretical yield (the maximum amount predicted by stoichiometry) and multiplying by 100. This value indicates how well the reaction performed in practice compared to the ideal.
To use the calculator, enter the actual yield and theoretical yield in the appropriate fields. The result is displayed as a percentage. For example, if you obtained 4 grams of product in a reaction that should theoretically produce 5 grams, the percent yield is (4/5) × 100 = 80%. This means 80% of the expected product was actually obtained.
This calculator is useful in organic, inorganic, or analytical chemistry labs, where yield is a crucial parameter for evaluating synthesis effectiveness. It is also applied in industrial processes to monitor production efficiency and in academic work to report experimental results. Percent yield helps identify losses or limitations in the reaction.
Important precautions: ensure both values are in the same mass unit (grams, kilograms, etc.). The actual yield should never exceed the theoretical yield (if so, it may indicate measurement error or contamination). Remember that theoretical yield is calculated from the limiting reactant. This tool only performs the calculation, it does not replace critical analysis of experimental data.
Frequently asked questions
What does a percent yield above 100% mean?
It indicates that the actual yield is greater than the theoretical yield, which is impossible under ideal conditions. It may be due to measurement errors, impurities in the product, or residual solvent.
Can I use different units for actual and theoretical yield?
No, both must be in the same unit (e.g., grams). Otherwise, the calculation will be incorrect.
How do I calculate the theoretical yield?
The theoretical yield is obtained from the stoichiometry of the reaction, considering the limiting reactant. Use a stoichiometry calculator or perform manual calculation based on molar masses.
What is a good percent yield?
It depends on the reaction. In organic syntheses, yields above 80% are considered good. Low yields may indicate losses or side reactions.
Does this calculator work for any type of reaction?
Yes, as long as you have the actual and theoretical yield values. It works for reactions in solution, solid, or gas phase, provided the units are consistent.