Percentage Calculator
Calculate percentage of a number, percentage change, increase/decrease, and find the original value from a percentage.
How to use the Percentage Calculator
-
Choose the percentage mode.
-
Enter your numbers.
-
Copy the calculated result.
How to calculate percentages
Percentages express a number as a fraction of 100. They're everywhere — discounts, tips, tax, growth rates, test scores. This calculator covers the four most common scenarios: ① what is X% of Y? (for discounts and tips), ② X is what percent of Y? (for test scores and allocation), ③ percentage change from X to Y (for growth rates), and ④ the original value before a percentage increase or decrease. All math runs instantly in your browser.
Key features
- Calculate X% of a number
- Find what percent one number is of another
- Measure percentage change (increase/decrease)
- Reverse-calculate the original value before a percentage was applied
Frequently asked questions
How do I calculate a 20% tip?
Use 'X% of Y': enter 20 as the percentage and the bill amount as the number. The result is your tip.
What's the difference between percentage points and percent?
Going from 10% to 15% is a 5 percentage point increase, but a 50% increase (5 is half of 10). This calculator works with percents, not percentage points.
Is my data stored?
No. All calculations run in your browser and nothing is saved.