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Percentage of a number calculator
Enter a percentage and a number and get the answer, for example 15% of 200 is 30. The formula is shown so you can check it by hand.
- Free
- No sign-up
- Runs in your browser
What is X% of Y?
X is what percent of Y?
Percentage change from A to B
Increase or decrease an amount by a percentage
X is P% of what number?
100% private — the calculation is done in your browser and nothing is sent to any server.
Next step
Keep going with your result in another tool. Nothing is uploaded.
How it works
Read the answer
The result appears at the top of the list.
Check the formula
The formula is shown under each result.
How to calculate a percentage of a number
To calculate a percentage of a number, multiply the number by the percentage and divide by 100. For example, 15% of 200 is 200 × 15 ÷ 100 = 30. In the calculator above, enter the percentage and the number in the section what is X% of Y, and the answer appears at the top of the results.
The formula
Result = number × percentage ÷ 100. A percentage means per hundred, so 15% is 15 per hundred, or 0.15. Multiplying by 0.15 is the same as multiplying by 15 and dividing by 100.
A worked example, step by step
You want to leave a 15% tip on a bill of 200. Step 1: turn 15% into a decimal, 0.15. Step 2: multiply, 200 × 0.15 = 30. The tip is 30 and the total is 230. The mental way gives the same answer: 10% of 200 is 20, half of that is 10 for the 5%, and 20 + 10 = 30. For a percentage that is not round, such as 7.5%, use the calculator and check the result against the closest easy percentage.
Examples
| Percentage | Of the number | Result |
|---|---|---|
| 10% | 250 | 25 |
| 15% | 200 | 30 |
| 20% | 85 | 17 |
| 7.5% | 1,200 | 90 |
| 33% | 90 | 29.7 |
Mental shortcuts
- 10%: move the decimal point one place to the left.
- 5%: half of 10%.
- 1%: move it two places.
- 15%: 10% plus 5%.
- 25%: a quarter; 50% is half; 75% is three quarters.
Where you use it
- Tips and service charges at restaurants.
- Discounts, taxes and commissions.
- Interest and returns on money.
- Shares and portions in recipes and budgets.
Private by design
The calculation runs in your browser as you type. The amounts you enter are never sent to a server, so you can use real prices, invoices and quotes.
Frequently asked questions
What is 15% of 200?
30. Calculate 200 × 15 ÷ 100, or 200 × 0.15.
How do I calculate 20% of a number quickly?
Find 10% by moving the decimal point one place left, then double it.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. Use the what percent is X of Y calculator for that.
Is this converter free?
Yes. There is no sign-up and no limit, and it runs in your browser, so nothing you type is sent to a server.
Does it work on a phone?
Yes. It works in any modern mobile browser, and the result updates as you type.
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