Percentage Calculator
Work out percentages three ways — what is X% of Y, X is what percent of Y, and the percent increase or decrease from one number to another.
Three percentage questions, one tool
Most everyday percentage problems are one of three shapes, and the calculator handles all of them. Pick a mode and enter two numbers:
- What is X% of Y? — (X ÷ 100) × Y. A 20% tip on a $150 bill is $30.
- X is what percent of Y? — X ÷ Y × 100. Scoring 30 out of 150 is 20%.
- Percent change from X to Y — (Y − X) ÷ X × 100. Going from 150 to 180 is a 20% increase.
Increase vs decrease
The percent-change mode shows a positive number for an increase and a negative one for a decrease, so it works for discounts, markups, growth and drops alike. For business pricing, see the markup calculator; for a quick average, the average calculator.
Frequently asked questions
How do you calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number: X% of Y = (X ÷ 100) × Y. For example, 20% of 150 is 0.20 × 150 = 30. Use the “What is X% of Y?” mode above and enter your numbers.
How do I find what percent one number is of another?
Divide the first number by the second and multiply by 100: X ÷ Y × 100. For example, 30 out of 150 is 30 ÷ 150 × 100 = 20%. Switch to the “X is what percent of Y?” mode for this.
How do you calculate percentage increase or decrease?
Subtract the old value from the new, divide by the old value, and multiply by 100: (new − old) ÷ old × 100. Going from 150 to 180 is (180 − 150) ÷ 150 × 100 = 20% increase. The “Percent change” mode does this.