Percentage Calculator
Calculate percentages, percentage change, and what percent one number is of another.
What Is This Tool?
A free calculator for the three most common percentage questions: finding a percentage of a number, figuring out what percent one number is of another, and calculating percentage increase or decrease between two values.
How to Use
- Choose the calculation mode that matches your question using the tabs.
- Enter the numbers into the input fields.
- The result updates automatically as you type.
Common Use Cases
- Calculating a discount or sale price
- Figuring out a tip or commission percentage
- Comparing test scores or grades as percentages
- Measuring growth or decline between two values, like sales or expenses
Tips & Tricks
- For percentage change, a negative result means a decrease and a positive result means an increase.
- Use 'X is what % of Y' to quickly check ratios, like how much of a budget has been spent.
Frequently Asked Questions
What are the three calculation modes and when do I use each?
'What is X% of Y' finds a portion of a number (like a discount). 'X is what % of Y' finds a ratio (like a test score). 'Percentage change' compares two values to find growth or decline (like a price change over time).
Why does percentage change show a negative number sometimes?
A negative result means the second value is smaller than the first — a decrease. A positive result means it increased. The sign tells you the direction of change, and the magnitude tells you how much.
How do I calculate a discount price using this tool?
Use 'What is X% of Y' with X as the discount percentage and Y as the original price to find the discount amount, then subtract it from the original price for the final cost.
Can percentage change be more than 100%?
Yes. If a value more than doubles, the percentage increase exceeds 100% — for example, going from 10 to 25 is a 150% increase.
Is my data processed on a server?
No. All calculations run instantly and locally in your browser using basic arithmetic — nothing is sent anywhere.
Calculate percentages, percentage increase/decrease, and what percent one number is of another. Free and instant, right in your browser.