What is a percentage?
A percentage expresses a value as parts per hundred. For example, 25% means one quarter.
How to calculate a percentage of a number
Divide the percentage by 100 and multiply by the number.
Result = percentage ÷ 100 × number
How to find what percentage one number is of another
Divide the value by the total and multiply by 100. A zero total is undefined.
Percentage = value ÷ total × 100
How to find the whole from a percentage
Divide the known value by the percentage written as a decimal.
Whole = value ÷ (percentage ÷ 100)
Percentage formulas and worked examples
| Question | Result |
|---|---|
| 25% of 200 | 50 |
| 15% of 80 | 12 |
| 50 is what percent of 200? | 25% |
| 20 is what percent of 200? | 10% |
| 50 is 25% of what? | 200 |
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100, then multiply it by the number.
How do I find what percent one number is of another?
Divide the value by the total and multiply by 100.
How do I calculate the original number from a percentage?
Divide the value by the percentage expressed as a decimal.
How do I calculate 20% of a number?
Multiply the number by 0.2.
Can percentages be greater than 100%?
Yes. They represent more than the full reference amount.
Can percentages be negative?
Yes, when the mathematical context permits.