Percentage Calculator
Three common percentage calculations, all updating live as you type.
What this tool does
This tool covers the three percentage calculations people search for most often: finding a percentage of a number (X% of Y), finding what percentage one number is of another (X is what % of Y), and finding the percentage change between an original and a new value. All three update live as you type, with no "calculate" button to click.
Example use case
Figuring out a 20% tip on a $150 bill, checking what percentage 30 correct answers is out of 150 questions, or calculating how much a price increased from $150 to $180 (a 20% increase) are all everyday calculations that are easy to get wrong doing mental math, especially with decimals involved.
Percentage change, increase, and decrease
Percentage change is calculated as (new − original) ÷ original × 100. A
positive result means an increase, a negative result means a decrease — this tool labels which one
you're looking at so the sign doesn't need interpreting.