Percent of a number calculator
Enter a percentage and a number to get that share of it. Switch to “Find the whole” when you know the part and its percentage but not the total.
What is X% of Y?
Settings
20% of 150
20% of 150 is 30.
Formula
Result = (Percentage ÷ 100) × Number
Steps
- Turn the percentage into a decimal: 20 ÷ 100 = 0.2
- Multiply by the number: 0.2 × 150 = 30
Recent calculations
Exact decimal arithmetic, calculated in your browser.
How to find a percentage of a number
Divide the percentage by 100 to turn it into a decimal, then multiply it by the number. For 15% of 60, that’s 15 ÷ 100 = 0.15, and 0.15 × 60 = 9.
The order of the multiplication doesn’t matter, which gives you a useful shortcut: 8% of 50 is the same as 50% of 8, which is 4. When one of the two numbers is easier to work with as a percentage, swap them.
Working backward to the total
If you know that 18 is 40% of something, divide 18 by 0.4 to get 45. Check it by going forward again: 40% of 45 is 18. Use this when a receipt shows a deposit and its percentage, or a progress bar shows how much is done and what share that is.
This is a different problem from undoing a percentage change. If a price rose by 40% to reach 18, the original was 18 ÷ 1.4 ≈ 12.86, not 45. The reverse percentage calculator handles that case.
Percentages above 100 and below 1
Nothing stops the percentage from going over 100: 120% of 85 is 102, more than you started with. Very small percentages work the same way. 0.25% of 4,000 is 10. If you work with basis points, 1 basis point is 0.01%, so 25 basis points of 4,000 is also 0.25% of 4,000.
Questions people ask
Guides that use this calculator
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