Percentage calculator: five common percentage questions
One tool for the percentage questions that come up most: find a share, find a percent, add or remove a percentage, or work back to the whole.
How to use this calculator
- Choose the question that matches yours.
- Enter X and Y in the two boxes; the labels in the result show how they are used.
- For 'X is P% of what number', enter the known amount as X and the percentage as Y.
- Read the answer and the short formula below it.
Worked examples
Example 1
What is 15% of 2,400?
You enter
| What do you want to find? | X% of Y |
|---|---|
| X | 15 |
| Y | 2,400 |
You get
| 15% of 2,400 | 360 |
|---|
Example 2
What percent of 2,400 is 360?
You enter
| What do you want to find? | X is what % of Y |
|---|---|
| X | 360 |
| Y | 2,400 |
You get
| 360 is what % of 2,400 | 15% |
|---|
Example 3
Increase 2,400 by 12%.
You enter
| What do you want to find? | Increase Y by X% |
|---|---|
| X | 12 |
| Y | 2,400 |
You get
| 2,400 increased by 12% | 2,688 |
|---|---|
| Change | 288 |
How it works
A percentage is just a fraction out of 100. 15% of 2,400 means 15 / 100 x 2,400.
Adding then removing the same percentage does not bring you back: add 20% to 100 to get 120, then take 20% off 120 and you get 96.
Formula
X% of Y = X / 100 x Y. X is what % of Y = X / Y x 100. Increase = Y x (1 + X / 100). Whole = part / (percentage / 100).
Common questions
How do I find a percentage increase between two numbers?
Use the percentage change calculator.
How do I take a percentage off?
Choose 'Decrease Y by X%'.
Why does the order matter?
Percentages of different bases give different answers.
Calculators give estimates for learning and planning. They are not financial, tax, legal or medical advice, and results depend entirely on the numbers you enter. Check rates, limits and rules with an official source or a qualified professional before acting.