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 — 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 — nothing you type is transmitted, logged, or stored anywhere. You can even use it offline once the page has loaded.