Percentage Calculator
Work out X% of a number, what percent one number is of another, the percentage change between two values, and price increases or discounts.
Runs in your browser. Nothing is uploaded.
About the Percentage Calculator
Percentages come up constantly: discounts while shopping, tips and taxes, grade scores, salary rises, price changes, growth figures in reports and conversion rates in analytics. The formulas are simple, but it is easy to mix up which number to divide by.
This page puts the four most common questions side by side: what is X% of a number, what percentage one number is of another, the percentage change between two values, and the result of increasing or decreasing a value by a percentage. Each answer comes with a plain-English sentence and the formula, so you can check the working.
How to use the Percentage Calculator
- 1
Pick the question that matches yours: four calculators sit side by side.
- 2
Type your two numbers. The answer, a plain-English sentence and the formula update as you type.
- 3
For a decrease or discount, enter a negative percentage in “Increase or decrease”, for example −20.
- 4
Press the copy button next to an answer to paste it elsewhere.
Examples
What is 15% of 80?12
15% × 80 = 1245 is what percent of 60?75%
45 ÷ 60 × 100 = 75%Percentage change from 50 to 65+30%
(65 − 50) ÷ 50 × 100 = 30% (increase)Decrease 250 by 20%200
250 × (1 − 20%) = 200Good to know
- Answers are rounded to 4 decimal places for display.
- Percentage change is measured against the starting value, so a change from 0 cannot be calculated.
- Commas are read as thousands separators (1,250 is one thousand two hundred and fifty).
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. 15% of 80 is 0.15 × 80 = 12.
How is percentage change calculated?
Subtract the old value from the new one, divide by the old value and multiply by 100. From 50 to 65 is (65 − 50) ÷ 50 × 100 = 30%.
Why doesn’t a 20% decrease undo a 20% increase?
Each percentage applies to a different base. 100 plus 20% is 120, but 20% of 120 is 24, so decreasing by 20% gives 96. To undo +20%, decrease by about 16.67%.
Is anything I enter saved?
No. Calculations run on your device and nothing is stored or sent.
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