Percentage calculator
Nothing you type leaves this device.
The short answer
Twenty per cent of 250 is 50. To take any percentage of any number, multiply the two together and divide by 100.
There is no server in this. The arithmetic runs in the page, which is why the answer is there before you have finished typing the second number.
The formula
part = whole × percent ÷ 100
Worked examples
- 20% of 250
- 50
- 42 out of 240
- 17.5%
- 240 → 270
- 12.5%
Reference table
| Percentage | of 50 | of 100 | of 250 | of 1,000 |
|---|---|---|---|---|
| 5% | 2.5 | 5 | 12.5 | 50 |
| 10% | 5 | 10 | 25 | 100 |
| 15% | 7.5 | 15 | 37.5 | 150 |
| 20% | 10 | 20 | 50 | 200 |
| 25% | 12.5 | 25 | 62.5 | 250 |
| 50% | 25 | 50 | 125 | 500 |
How to use it
- 01Pick the question you actually meanChoose one of the three modes: a percentage of a number, what percent one number is of another, or the change between two numbers.
- 02Type the two figuresEnter your numbers in the two fields. The answer updates as you type and stays pinned above the keyboard.
- 03Check the restated questionThe line under the fields restates what is being asked in words, so you can confirm the calculator understood you before trusting the figure.
Also searched for
Searches that land here include percentage calculator, percent of a number, percentage change, percentage increase calculator and how to add VAT.
About percentages
The three questions people actually mean
Almost every percentage problem is one of three. What is fifteen per cent of two hundred and forty? That is a share of a whole. Forty-two is what per cent of two hundred and forty? That is a proportion. And what is the change from two hundred and forty to two hundred and seventy? That is growth. The three tabs above are those three questions, in that order, because guessing which one a visitor wants is how calculators end up wrong.
Percentage points are not per cent
A rate that moves from four per cent to six per cent has risen by two percentage points and by fifty per cent. Both statements are true and they are not the same number. Newspapers mix them constantly. If you are checking a figure in an article, work out which one is meant before deciding it is wrong.
Questions people ask
How do I add VAT to a price?
Use the first tab: twenty per cent of the net price gives the VAT, and adding it gives the gross. To go the other way, from a gross price back to net, divide by 1.2 — do not take twenty per cent off the gross, which is the most common mistake in this arithmetic and always gives you too little.
Why does a 50% rise followed by a 50% fall not get me back?
Because the second percentage is taken from a bigger number. A hundred rising by half is a hundred and fifty; half of a hundred and fifty is seventy-five. Percentages compound against whatever the current value is, which is also why a discount stacked on a discount is never the sum of the two.
Is the calculation happening on a server?
No. It is a few lines of arithmetic running in the page, which is why it answers instantly and keeps answering with your connection off. Nothing you type is sent, logged or stored.