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Percent Recovery Calculator

This calculator works out the percent recovery for a chemistry experiment or laboratory procedure. Enter the initial and recovered amounts in your chosen unit (grams, moles, millilitres and more) to see your recovery percentage and the amount lost.

Updated 13 October 2026

How to calculate percent recovery

Divide the amount you recovered by the amount you started with and multiply by 100. Percent recovery measures how much of a substance was successfully retrieved after a purification, extraction or synthesis procedure, compared to the theoretical amount you started with. A 100% recovery would mean no substance was lost; in practice, some loss is almost always expected.

Percent recovery formula

% Recovery = (Recovered amount / Initial amount) × 100

Amount lost = Initial amount - Recovered amount

There is no single pass mark for percent recovery. What counts as a good result depends on the method, so check what your teacher or the procedure expects.

Why this works: Expressing recovery as a percentage of the initial amount gives a standardised measure that is comparable across experiments of different scales.

Percent recovery examples

What is the percent recovery if 4.25 g of pure product is recovered from 5.00 g of impure compound?

  1. % Recovery: (4.25 / 5.00) × 100 = 85%
  2. Lost: 5.00 - 4.25 = 0.75 g

Answer: 85% recovery

What is the percent recovery when 6.2 mmol is recovered from 10 mmol of crude product?

  1. % Recovery: (6.2 / 10) × 100 = 62%
  2. Lost: 3.8 mmol

Answer: 62% recovery

What is the percent recovery when 48.5 mL is recovered from 50 mL of solution?

  1. % Recovery: (48.5 / 50) × 100 = 97%
  2. Lost: 1.5 mL

Answer: 97% recovery

What is the percent recovery if 2.50 g of crude aspirin gives 1.93 g of pure crystals?

  1. % Recovery: (1.93 / 2.50) × 100 = 77.2%

Answer: 77.2% recovery

What is the percent recovery of 840 g of extract from 1,000 g of raw material?

  1. % Recovery: (840 / 1000) × 100 = 84%
  2. Lost: 160 g

Answer: 84% recovery

When is percent recovery used?

Use percent recovery to check how much of a substance survives a purification or extraction step.

  • A-level and university chemistry: A common calculation in A-level chemistry practicals and university lab reports where students must assess the efficiency of a synthesis or purification.
  • Pharmaceutical manufacturing: Tracking how much product survives each purification step to identify where product is being lost unexpectedly.
  • Environmental analysis: Measuring how much of a contaminant is recovered when extracting samples from soil or water, used to validate analytical methods.
  • Food and ingredient processing: Calculating extraction efficiency when isolating compounds such as proteins, oils or pigments from raw food materials.

Why is my percent recovery over 100% or very low?

A recovery over 100% means more was recovered than you started with. It is not an excellent result: it points to impurities, leftover solvent or a weighing error (or a slip in the calculation), so investigate it rather than report it as a positive result.

Low percent recovery is usually caused by product left in apparatus, incomplete transfer between vessels, product dissolving in wash solvents, or incomplete precipitation during crystallisation. High losses at a specific step should prompt technique review.

Other calculations to use with percent recovery

How to calculate percent recovery in Excel

=(B1/A1)*100

Put the initial amount in A1 and the recovered amount in B1. The formula already multiplies by 100, so 5.00 and 4.25 give 85; leave the cell as a normal number rather than percentage format. For amount lost: =A1-B1.

Percent recovery without a calculator

Divide the recovered amount by the starting amount and multiply by 100: 4 g recovered from 5 g is 4 ÷ 5 × 100 = 80%. If you recovered about 4.5 g from 5 g, that is 90%.

Common percent recovery mistakes

Confusing percent recovery with percent yield

Percent yield is calculated from the theoretical yield based on stoichiometry and is used for reactions. Percent recovery is used for purification procedures where no chemical reaction occurs (recrystallisation, extraction, filtration).

Not accounting for residual solvent in the recovered mass

If the product has not been fully dried before weighing, residual solvent will inflate the recovered mass and overstate the percent recovery. Always dry thoroughly and record mass after drying.

Sources and checks

The maths on this page uses standard formulas, shown in the worked examples above.

Checked on 13 October 2026. Read how we check our calculators. Spotted a mistake? Tell us and we will put it right.

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