Calculators · Free Tool
Percentage Calculator
Calculate what X% of Y is, what percent X is of Y, and percentage increase or decrease.
What is X% of Y?
X is what percent of Y?
Percentage change from X to Y
About this tool
Three percentage calculations in one tool: find X% of a number, find what percent one number is of another, and find the percentage change (increase or decrease) between two values. Results update as you type.
It covers the everyday cases, including discounts, tips, tax, commissions, growth rates, and score percentages, without you having to remember which way the formula goes.
Common uses
- Work out the final price after a 25% discount
- Find what percent of a target you have reached
- Measure month-over-month growth between two revenue figures
Frequently asked questions
How is percentage change calculated?
Percentage change = (new − old) ÷ old × 100. A result above zero is an increase, below zero a decrease. Note the divisor is always the original value.
Why is a 50% loss not undone by a 50% gain?
Because each percentage applies to a different base: 100 − 50% = 50, and 50 + 50% = 75. After a 50% drop you need a 100% gain to get back to the start.
Is my data uploaded to a server?
No. This tool runs entirely in your browser using JavaScript, so nothing you type is transmitted, logged, or stored anywhere. You can even use it offline once the page has loaded.