Percentage Calculator
Three percentage questions, answered as you type. Find a percentage of a number, work out what percent one value is of another, or calculate a percentage change.
How percentages work
A percentage is simply a fraction out of 100. "Per cent" literally means "per hundred", so 25% is the same as 25⁄100, or 0.25. Converting between a percentage and a decimal is the key to almost every percentage problem: divide by 100 to get the decimal, multiply by 100 to get the percentage.
The three calculations above
- X% of Y — scaling a number by a percentage. Handy for discounts, tax, tips and commissions.
- X is what % of Y — expressing one number as a share of another. Useful for scores, progress and proportions.
- Percentage change — how much a value grew or shrank, relative to where it started. The basis for growth rates and markdowns.
Everyday examples
- A $80 jacket at 25% off saves you $20, costing $60.
- Scoring 45 out of 60 on a test is 75%.
- A salary rising from $50,000 to $55,000 is a 10% increase.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 20% of 150 is 150 × 20 ÷ 100 = 30. The first calculator above does this instantly.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, 30 is 30 ÷ 150 × 100 = 20% of 150.
How is percentage increase or decrease calculated?
Subtract the old value from the new value, divide by the old value, then multiply by 100. A positive result is an increase; a negative result is a decrease.
Is my data private?
Yes. Every calculation runs locally in your browser with JavaScript. Nothing you enter is uploaded or stored.