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Free tool

Percentage Calculator

Work out a percentage of a number, what percent one number is of another, and percentage increase or decrease, with the formula shown for every answer.

How to use the percentage calculator

  1. Choose the calculation you need.
  2. Enter your numbers. The answer and the formula appear straight away.
  3. Use the result to check discounts, price rises, marks or budgets.

Frequently asked questions

How do I calculate a percentage increase?

Subtract the old value from the new value, divide the result by the old value, then multiply by 100. A change from 50 to 65 is (65 − 50) ÷ 50 × 100 = 30% increase.

Why is a 50% increase followed by a 50% decrease not the original number?

Because each percentage is taken from a different starting value. 100 increased by 50% is 150; 150 decreased by 50% is 75.

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