How do I calculate a percentage of a number?

Divide the percentage by 100 and multiply by the number. So 20% of 150 is 0.20 × 150 = 30. The "% of a number" mode does this instantly, which is handy for tips, discounts and shares of a total.

How do I find what percentage one number is of another?

Divide the first number by the second and multiply by 100. For example 43 out of 50 is (43 ÷ 50) × 100 = 86%. The "X is what %" mode handles this, which is the calculation behind turning a test score into a grade.

How is percentage change worked out?

Subtract the original value from the new one, divide by the original, and multiply by 100. Going from 50 to 75 is (75 − 50) ÷ 50 × 100 = a 50% increase; going from 80 to 60 is a 25% decrease. The "% change" mode tells you both the size and the direction.

Is anything I type sent to a server?

No. Everything runs inside your browser, so the work you do here stays on your own device and nothing is uploaded. There is no sign-up and no limit on how many times you use it, and once the page has loaded it keeps working with no connection.

Percentage Calculator

A simple percentage calculator with three modes: find X% of a number, work out what percent one number is of another, and calculate the percentage increase or decrease between two values. Free, in your browser, no sign-up.

Free, every tool
No sign-up, no app
Private in your browser
Instant results
Works offline after first load

Percent

ofNumber

Result

20% of 150 is 30.

How to use it

1
Pick a mode

Choose "% of a number", "X is what %", or "% change" depending on the question you have.
2
Type the numbers

Enter your two values in the boxes. The result updates as you type, with no button to press.
3
Read the answer

See the result and a plain-language sentence that explains what it means.

When it comes in handy

Discounts and tips

Work out 15% of a bill, or how much a sale price knocks off the original.

Scores and marks

Turn a raw score like 43 out of 50 into a percentage for a quick grade check.

Change over time

Find the percentage rise or fall between two figures, such as a price or a population.

Instant, exact & 100% in your browser

The conversion runs right here in your browser using exact, standard factors. Nothing you type is sent to a server, there is no sign-up and no limit, and once the page has loaded it keeps working even with no connection.

Frequently asked questions

How do I calculate a percentage of a number?: Divide the percentage by 100 and multiply by the number. So 20% of 150 is 0.20 × 150 = 30. The "% of a number" mode does this instantly, which is handy for tips, discounts and shares of a total.
How do I find what percentage one number is of another?: Divide the first number by the second and multiply by 100. For example 43 out of 50 is (43 ÷ 50) × 100 = 86%. The "X is what %" mode handles this, which is the calculation behind turning a test score into a grade.
How is percentage change worked out?: Subtract the original value from the new one, divide by the original, and multiply by 100. Going from 50 to 75 is (75 − 50) ÷ 50 × 100 = a 50% increase; going from 80 to 60 is a 25% decrease. The "% change" mode tells you both the size and the direction.
Is anything I type sent to a server?: No. Everything runs inside your browser, so the work you do here stays on your own device and nothing is uploaded. There is no sign-up and no limit on how many times you use it, and once the page has loaded it keeps working with no connection.