Percentage Calculator
Three percentage calculators in one: work out a percent of a number, find what percent one number is of another, and get the percentage change between two values. Results update as you type.
- % of a number
- Percent change
- Updates as you type
- No sign-up
What is X% of Y?
X is what percent of Y?
Percentage change from X to Y
How to use
- Choose the box that matches your question: percent of a number, what percent, or percent change.
- Type the two numbers. The answer appears right away.
- Click the answer to copy the number.
- Clear a field to start a new calculation.
Percentage formulas
X% of Y = X ÷ 100 × Y. X is what percent of Y = X ÷ Y × 100. Percentage change = (new − old) ÷ |old| × 100. A positive result is an increase, a negative result is a decrease. For example, a price going from 80 to 100 is a 25% increase, but going back from 100 to 80 is a 20% decrease, because the base value is different.
Everyday uses
Discounts and sales tax, test scores, interest, tips and growth rates all use percentages. For restaurant bills use the tip calculator.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percent and divide by 100. 15% of 200 is 15 × 200 ÷ 100 = 30.
How do I find the percent increase?
Subtract the old value from the new value, divide by the old value and multiply by 100.
Why is a 20% increase then a 20% decrease not back to the start?
The second change is applied to a bigger number, so it removes more than the first one added.
Can I use decimals and negative numbers?
Yes. Both decimals and negative numbers work.