Percent Yield Calculator

All chemistry tools

Compare your actual lab results with the theoretical maximum to determine reaction efficiency.

Reaction Data

Actual Yield (Obtained)

Theoretical Yield (Predicted)

Yield Analysis

Enter your yields to see the efficiency breakdown

About this calculator

Overview

Percent yield is the ratio of the actual amount of product obtained in a chemical reaction to the theoretical amount of product calculated from the limiting reactant. It is a key indicator of experimental or industrial efficiency. Yields are rarely 100% due to factors like incomplete reactions, side reactions that produce different products, and losses during filtration or purification.

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Pro Tips

Ensure both values use the exact same unit (e.g., both grams or both moles).
The theoretical yield must always be the larger number in a perfect world.
Keep track of spills and residue in beakers—every milligram counts!
Identify your limiting reactant first before calculating theoretical yield.

Fun Facts

"If a reaction has a 90% yield for each step, a 10-step synthesis would have a total yield of only 35% (0.9^10)."
"Pharmaceutical companies spend billions to increase yields by even 1%, as it directly impacts profitability and waste."
"Yields over 100% usually mean your product is still wet or contains impurities (like leftover solvent or extra salt)."
"The 'Atom Economy' is a related but different concept that measures how many reactant atoms end up in the final product."

Formula: \text{Percent Yield} = \left( \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \right) \times 100\%