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Percentage Calculator
Every percentage question, answered.
15% of 200
30
About the Percentage Calculator
Free percentage calculator. Work out what % one number is of another, find X% of a value, and calculate percentage increase or decrease instantly.
Everything is calculated instantly in your browser — nothing you type is uploaded or stored. Bookmark Calcooly for the next time you need it.
How to use the Percentage Calculator
- 1Pick the type of question: % of a number, X is what %, or % change.
- 2Fill in the two values.
- 3The answer updates as you type.
Frequently asked questions
How do I find a percentage of a number?+
Choose “% of a number”, enter the percentage and the value — for example 15% of 200 gives 30.
How is percentage change calculated?+
It's the difference between the new and old value, divided by the old value, times 100. From 80 to 100 is a 25% increase.
Is my data private?+
Yes. Every calculation runs in your browser — the numbers you enter are never sent to a server or stored anywhere.