Percentage Calculator
Find percentages, increases and decreases with clear results.
What is X% of Y?
Increase / Decrease
How to use this tool
Enter a percentage and a number in the first calculator. To compare two values, enter the original value and the new value in the second calculator. Results are rounded to two decimal places.
A worked example
What is 15% of 240? Divide 15 by 100 and multiply by 240: the answer is 36. A price changing from 80 to 100 increases by 25%, because (100 − 80) ÷ 80 × 100 = 25.
How it works & what to check
Percentage value = percentage ÷ 100 × number. Percentage change = (new − old) ÷ old × 100. The original value cannot be zero; a percentage change from zero is undefined.
Common questions
How do I calculate a discount?
Find the discount amount, then subtract it from the original price. A 15% discount on 240 saves 36, so the final price is 204.
Why is an increase different from a decrease?
The starting value is the denominator. An increase from 80 to 100 is 25%, while a decrease from 100 to 80 is 20%.
Can I use decimals?
Yes. Enter decimal percentages or amounts. Displayed results are rounded, so keep unrounded values for chained calculations.