Percentage Calculator
The three percentage questions everyone googles, answered instantly.
About this tool
The three percentage calculations everyone needs: what is X% of Y, X is what percent of Y, and the percentage change between two numbers. Results update as you type - no button, no page reload.
How do I calculate a percentage increase?
Subtract the old value from the new one, divide by the old value, multiply by 100. The third row does it for you, sign included.
Why three separate forms?
Because the three questions are different formulas, and mixing them up is the most common percentage mistake.