Math & Conversion
Percentage Calculator
Find a percentage of a value, compare two values, or calculate a percentage increase or decrease.
How to use
Choose a calculation, then enter values A and B. For a ratio, A is the amount being compared and B is the reference value.
Formula
A percent of B = A × B ÷ 100 · A as a percent of B = A ÷ B × 100 · New value = A × (1 ± B ÷ 100)
Example
What is 15% of 200?
200 × 15 ÷ 100 = 30.
Frequently asked questions
- How do I find what percent A is of B?
- Divide A by B and multiply by 100. The ratio is undefined when B is zero.
- Does a 15% increase followed by a 15% decrease return to the original value?
- No. The decrease is applied to the increased value, so the result is slightly lower than the starting value.