What it does
A collection of the most common percentage calculations in one place:
- What is X% of Y?
- X is what percent of Y?
- Percentage change between two values (increase/decrease)
- Add a percentage to a value (e.g. add 20% tax)
- Subtract a percentage from a value (e.g. apply a 15% discount)
Everything runs entirely in your browser — no data is ever sent anywhere.
Try it
How it works
Depending on the selected calculation type, one of the following formulas is applied:
| Calculation | Formula |
|---|---|
| What is X% of Y? | (X / 100) × Y |
| X is what percent of Y? | (X / Y) × 100 |
| Percentage change from X to Y | ((Y − X) / X) × 100 |
| Add X% to Y | Y + (X / 100) × Y |
| Subtract X% from Y | Y − (X / 100) × Y |
Notes
- A percentage change result is shown as positive for an increase and negative for a decrease.
- Dividing by zero (e.g. "X is what percent of Y?" with
Y = 0, or a percentage change starting fromX = 0) is not mathematically defined and is reported as such rather than showing a misleading number. - Inputs accept decimals (e.g.
12.5) and negative numbers.