The formula
Percent = part ÷ whole × 100
The “whole” is the number after the word of. In “what percent is 18 of 24?”, 18 is the part and 24 is the whole.
Examples
- Test score: 42 correct out of 50 → 42 ÷ 50 × 100 = 84%
- 18 of 24 → 0.75 × 100 = 75%
- Budget: $450 rent of a $1,800 paycheck → 25%
- 7 of 8 → 87.5%
- 150 of 120 → 125% (the part can be bigger than the whole)
Fraction to percent chart
| Fraction | Decimal | Percent |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.3333 | 33.33% |
| 2/3 | 0.6667 | 66.67% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 5/8 | 0.625 | 62.5% |
| 7/8 | 0.875 | 87.5% |
| 1/10 | 0.1 | 10% |
Percent vs percentage points
If an interest rate rises from 4% to 5%, it went up 1 percentage point — but that’s a 25% increase relative to the old rate ((5 − 4) ÷ 4 × 100). News headlines mix these up all the time. For relative change, see the percent change guide.
FAQ
What percent is 25 of 200?
25 ÷ 200 × 100 = 12.5%.
How do I turn a test score into a percent?
Divide points earned by points possible and multiply by 100. 38 out of 45 = 84.4%.
Can a percentage be more than 100%?
Yes. If the part is larger than the whole (150 of 120), the result is over 100% — common with growth and price changes.
How do I find the whole if I know the percent?
Whole = part ÷ (percent ÷ 100). If 30 is 20% of a number, the number is 30 ÷ 0.20 = 150.
Related
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