“Percent” means “per hundred”, so 15% is 15 out of every 100, or 0.15. Every percentage question is a version of the same equation with a different unknown.
Two questions, one tool
- What is 15% of 240? Enter 15 and 240.
- What percent of 240 is 36? Enter 240, then type 36 in the result; the percentage is solved.
Mental shortcut
Find 10% by moving the decimal point one place left, then scale: 15% is 10% plus half of 10%.
Inputs explained
| Field | What to enter |
|---|---|
| Percentage | In % |
| Of number | A number |
Example values
How the main result changes when Percentage changes and everything else stays at the example values above:
| Percentage (%) | Result |
|---|---|
| 7.5 | 18 |
| 11.25 | 27 |
| 15 | 36 |
| 18.75 | 45 |
| 22.5 | 54 |
| 30 | 72 |
Formula
Result = P ÷ 100 × numberP = result ÷ number × 100Worked example
15% of 240 = 0.15 × 240 = 36.
Reverse: 39.6 is 39.6 ÷ 240 × 100 = 16.5% of 240.
Key terms
- Percent
- A ratio expressed per hundred.
- Base
- The number the percentage is taken of.
- Percentage point
- The arithmetic difference between two percentages.
Frequently asked questions
Is X% of Y the same as Y% of X?
Yes. 8% of 50 equals 50% of 8; both are 4.
How do I add a percentage to a number?
Multiply by (1 + P/100). Adding 20% to 50 gives 60.
How do I find a percentage increase?
Use the percentage change calculator.
What formula does the Percentage Calculator use?
Result = P ÷ 100 × number.
Can I work backwards from the result?
Yes. Type the result you want into Result and the calculator finds the matching percentage.