Percentage Calculator

Find a percentage of a number, a percent of a total, or the change between two numbers.

Runs in your browser — nothing is sent or saved.

How to work out a percentage

  1. Pick the box for the question you have.
  2. Type your two numbers.
  3. The answer appears right away, with no button to press.
  4. Change either number and the answer updates.

The three questions this tool answers

Most percentage jobs are one of three questions. "What is a percent of a number" finds a part, such as 10% of 250. "A number is what percent of another" tells you the share, such as how much of a 250 goal you reach with 25. "Percent change" measures a rise or a fall between two numbers, such as a price going from 80 to 100. This tool gives you all three in one place.

Why percent change can surprise you

Percent change is always measured against the starting number. A rise from 80 to 100 is a 25% increase, because the 20 gained is a quarter of 80. But a fall from 100 to 80 is only a 20% decrease, because the same 20 is a fifth of 100. So an increase and the matching decrease are not the same percentage. This trips people up in sales and stock figures.

Everyday uses

Work out a tip, a test score, a sales tax, a commission, or how much a bill went up this year. Because the tool shows the math live, you can try different numbers and see the effect straight away.

FAQ

How do I find a percentage of a number?

Use the first box. Enter the percent, then the number. For 15% of 200, the answer is 30.

Why is a 25% rise not cancelled by a 25% fall?

Each percentage is taken from a different starting number. A 25% rise then a 25% fall leaves you below where you began, because the fall is measured from the higher amount.

How do I turn a fraction into a percent?

Use the second box. Enter the top number, then the bottom number. For 3 out of 4, the answer is 75%.

Does it round the answer?

It shows up to four decimal places, which is enough for money and most schoolwork. Long decimals are trimmed.

Is anything sent to a server?

No. The math runs in your browser and nothing is saved.

Can it work out a percentage change?

Yes. To find a percentage increase, take the difference between the new and old numbers, divide by the old one, and multiply by 100. A drop works the same way and gives the percentage decrease. Percentage change covers both directions, and the percent off mode answers price questions like 20% off 50.