Percentage of a Number Calculator
Find X% of any number, like 20% of 85.
Good to know. X% of Y is always Y% of X. So 8% of 50 is 50% of 8, which is 4.
How it works
In plain words
Turn the percentage into a decimal by dividing it by 100, then multiply by the number.
The formula
result = (X ÷ 100) × Y
Worked example
20% of 85: 20 ÷ 100 = 0.2, and 0.2 × 85 = 17.
Sources
No outside data or rates: this is plain arithmetic.
10 automated tests check its answers on every change.
About the percentage of a number calculator
"Percent" means "per hundred". So 20% is 20 out of every 100, or 0.2 as a decimal. To find a percentage of a number, you scale the number by that decimal. That is all this calculator does, and it is the calculation behind most everyday percentage questions: a 15% tip, a 30% discount, a 5% pay rise or the 12% of your salary that goes into a pension.
A handy trick is that percentages are reversible: 20% of 85 is the same as 85% of 20. If one way round is hard to do in your head, try the other. For example, 4% of 75 is awkward, but 75% of 4 is obviously 3.
Percentages above 100 work too. 150% of 40 is 60, one and a half times the number. Negative numbers are allowed as well, which is useful for things like losses or temperature changes, though most everyday questions use positive values.
If you want to know what percentage one number is of another, for example "what percent of 85 is 17", use the "what percent is X of Y" calculator instead. If you want to add or remove a percentage from a price, the percentage increase and decrease calculator or the discount calculator will save you a step.
Questions people ask
How do I calculate a percentage of a number in my head?
Find 10% by moving the decimal point one place left, then scale. For 20% of 85: 10% is 8.5, so 20% is 17. For 5%, halve the 10% figure.
Is X% of Y the same as Y% of X?
Yes. Both are X × Y ÷ 100, so 20% of 85 and 85% of 20 are both 17. Use whichever is easier.
Can the percentage be more than 100?
Yes. 200% of a number is double it, and 150% is one and a half times it.
How do I find a percentage of a number on a phone calculator?
Multiply the number by the percentage and divide by 100. For 20% of 85, type 85 × 20 ÷ 100.