Free Percentage Calculator
Work out percentages three common ways — no signup, nothing sent to a server.
Result:
How to use the percentage calculator
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1
Pick a calculation type
Choose "X% of Y", "X is what % of Y", or "% increase/decrease" from the tabs above.
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2
Enter your numbers
Type the values into the fields — the result updates instantly as you type.
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3
Read the result
The answer appears below the inputs, ready to copy into wherever you need it.
Example use cases
Discounts & sale prices
Work out how much a percentage discount actually takes off a price.
Tips & bill splitting
Quickly figure a tip amount or a service charge on a restaurant bill.
Grades & test scores
Convert a raw score out of a total into a percentage.
Growth & shrinkage
See the percentage change between two figures, like revenue this month vs. last month.
Frequently asked questions
How do I calculate what X% of Y is?
Multiply Y by X, then divide by 100. For example, 20% of 150 is (150 × 20) ÷ 100 = 30.
How do I find what percent one number is of another?
Divide the first number by the second, then multiply by 100. For example, 30 is what % of 120 → (30 ÷ 120) × 100 = 25%.
How is percentage increase or decrease calculated?
Subtract the original value from the new value, divide by the original value, then multiply by 100. A positive result is an increase, a negative result is a decrease.
Is anything I type sent to a server?
No. Every calculation runs entirely in your browser — nothing is transmitted or logged.