Percentage Calculator
Work out percentages, ratios and percentage change instantly — in your browser.
About Percentage Calculator
Three quick percentage calculators in one: work out what a given percentage of a number is, find what percent one number is of another, and calculate the percentage increase or decrease from one value to another. Each updates live as you type.
The percentage-change calculator clearly labels an increase or a decrease, which is handy for prices, scores, discounts and statistics. Everything is computed locally in your browser.
Percent of a number
15% of 200
30
Also: 30 is 20% of 150, and 80 → 100 is a 25% increase.
Frequently asked questions
How do I calculate what percent one number is of another?
Divide the part by the whole and multiply by 100. Use the second calculator: enter the part and the whole to get the percentage directly.
How is percentage change calculated?
(new − old) ÷ |old| × 100. A positive result is an increase, a negative one a decrease; the tool labels which and shows the magnitude.
Can it handle decimals and negative numbers?
Yes. All fields accept decimals, and percentage change handles negative starting values using the absolute value as the base.
Is anything uploaded?
No. Every calculation runs locally in your browser.