Percentage of a Number Calculator
Enter a percentage and a number to find out what that percentage of it comes to. The answer, the working and the number with the percentage added or taken off all update as you type.
How to use this calculator
- Enter the percentage you want to take —
15for 15%. - Enter the number you want to take it from —
200. - Read the answer above the working. The question line under the inputs restates the sum in words, so you can check you have typed the two figures the way round you meant.
The four figures beside the answer cover the sums people usually want next: the working itself, the percentage written as a decimal, and the number with the percentage added on and taken off. That last pair is what you need when the percentage is a tax or a discount rather than an amount in its own right.
Nothing is submitted anywhere. The calculation runs in the page as you type, and the link in your address bar carries your figures, so it can be shared or bookmarked.
How to calculate a percentage of a number
A percentage is a fraction of 100. Dividing by 100 turns it back into that fraction, and multiplying applies it to your number — so the whole calculation is one division followed by one multiplication.
- Percentage — the rate you are taking, e.g. 20
- Number — the amount you are taking it from, e.g. 150
- Result — the answer, e.g. 30
To calculate 20% of 150, divide 20 by 100 and multiply the result by 150. That gives 20 ÷ 100 × 150 = 30, so 20% of 150 is 30.
The order matters when you do it in your head, but not to the answer: dividing 150 by 100 and multiplying by 20 gives the same 30. Use whichever is easier — dividing the round number by 100 is usually quicker.
Worked examples
| Percentage | Number | Result |
|---|---|---|
| 10% | 500 | 50 |
| 25% | 80 | 20 |
| 15% | 200 | 30 |
| 7.5% | 1,000 | 75 |
| 125% | 400 | 500 |
The fourth row shows that a decimal percentage is no harder than a whole one: 7.5 ÷ 100 × 1,000 = 75. The last shows what happens above 100% — 125% of 400 is 500, because you are taking the whole of 400 plus another quarter of it.