Percentage Calculator
Three common percentage calculations in one simple tool.
What is the Percentage Calculator?
This tool covers the three percentage questions people search for most often: finding a percentage of a number, finding what percentage one number is of another, and finding the percentage increase or decrease between two values. Switch between them with the tabs above — each updates its result live as you type.
How to use it
- X% of Y answers "what is 20% of 150?" — useful for tips, discounts and commissions.
- X is what % of Y answers "30 out of 150 is what percent?" — useful for test scores and completion rates.
- % Increase/Decrease answers "what's the percentage change from 80 to 100?" — useful for tracking growth, price changes or performance over time.
Percentage increase or decrease is calculated as (new − old) ÷ old × 100, and shows a negative number when the value has gone down. These three calculations cover the vast majority of everyday percentage questions, from working out a restaurant tip to comparing this month's sales figures with last month's, without needing to remember which formula applies to which situation.