Percentage Calculator
Seven instant percentage calculations in one place — of a number, change, increase, decrease, reverse and difference.
About this calculator
This free percentage calculator handles the seven percentage problems people run into most often, each in its own panel that updates instantly as you type. Work out what X% of a number is, find what percentage one number is of another, measure a percentage increase or decrease, add or subtract a percentage from a value, reverse a percentage to find the original number, and compute the percentage difference between two values.
Percentages appear everywhere — discounts and sales, exam scores, interest and tax, tips, statistics and data analysis. Instead of remembering each formula, pick the panel that matches your question and read the answer. Every calculation runs entirely in your browser, with nothing uploaded or stored, so it is fast and private.
Why use this tool
Seven calculations
Cover every common percentage question in one tool.
Instant answers
Results update as you type, with the formula made clear.
No setup
Just enter your numbers — no signup, no maths by hand.
Common use cases
- Work out a percentage of a number
- Find percentage increase or decrease
- Calculate what percent one number is of another
- Check a discount or markup
Frequently asked questions
Multiply the number by the percentage and divide by 100. For example, 15% of 200 = (15 ÷ 100) × 200 = 30.
Percentage change = ((new value − old value) ÷ old value) × 100. A positive result is an increase and a negative result is a decrease.
Add the percentage of the original to the original: new = original + (original × percent ÷ 100). For example, 200 increased by 15% is 230.
A percentage is a fraction of 100, while a percentile shows your rank relative to a group — the 90th percentile means you scored higher than 90% of people.
Use the “Add % to a number” panel: enter the price and the percentage, and it returns price + that percentage. Handy for tax, tips, and markups.