Percent Recovery Calculator

Calculate the efficiency of your purification or extraction process.

Initial/Theoretical Amount Starting mass or volume

Recovered/Actual Amount Final mass or volume obtained

Calculation Results

Please enter valid positive numbers. Initial amount must be greater than zero.

Understanding Percent Recovery

Percent recovery is a crucial metric used in chemistry, pharmacology, and material science to determine the efficiency of a purification or extraction process. It measures how much of the original substance was successfully isolated after a procedure, such as recrystallization, distillation, or chromatography.

The Percent Recovery Formula

The calculation is straightforward but vital for laboratory reporting:

            Percent Recovery = (Amount Recovered / Initial Amount) × 100
        

Percent Recovery vs. Percent Yield

While often used interchangeably, they are technically different:

Percent Recovery: Used when no chemical reaction has occurred (e.g., purifying a sample). You are looking at how much of the original material you still have.
Percent Yield: Used when a chemical reaction creates a new product. It compares the actual weight of the new product to the maximum theoretical weight possible based on stoichiometry.

Step-by-Step Calculation Example

Imagine you are purifying 5.00 grams of impure Aspirin through recrystallization:

Starting Material: 5.00g (Initial Amount)
Process: Dissolve in hot ethanol, filter, and cool.
Final Product: You weigh the dried, pure crystals and find you have 3.85g.
Calculation: (3.85 / 5.00) × 100 = 77.0% Recovery

Why Percent Recovery Matters

Low recovery rates (e.g., below 50%) might indicate that much of the product was lost in the solvent, left on the filter paper, or didn't crystallize properly. Conversely, a recovery over 100% usually suggests the sample is still wet with solvent or contains impurities, as you cannot "create" more of the original matter than you started with.