How to add a percentage to a value
- Choose “Increase a value” if it is not already selected.
- Type the value and the percentage increase.
- See the final value, highlighted, and the difference.
- Open “Show the calculation step by step” to see the formula.
The formula and examples
The increased value is the value × (1 + increase ÷ 100). If you add 15% to 100, the result is 100 × 1.15 = 115. If you add 10% to 250, it is 275.
It is useful for pay raises, rent increases, price hikes or adding a tip. To go the other way, use “Value before an increase”.
Good to know
- The increase can be more than 100%.
- Two increases in a row are not added together: the second is calculated on the result of the first.
- The result is rounded to make it easy to read.
Frequently asked questions
How much is 100 plus 15%?
115.
How do I add a percentage to a number?
Multiply the number by (1 + percentage ÷ 100). With 21%, multiply by 1.21.
How do I get back to the value before the increase?
Divide the final value by (1 + percentage ÷ 100), or use “Value before an increase”.
Is my data sent to any server?
No. The calculation runs in your browser.