Percentage Calculator
Three quick calculators for everyday percentages. Everything updates live and stays on your device.
What is X% of Y?
X is what percent of Y?
Percentage change from X to Y
Free online percentage calculator
Percentages come up everywhere — tips at a restaurant, sales tax, discounts, grades, interest rates and statistics. This calculator bundles the three most common percentage questions into one place: finding a percentage of a number, working out what percent one number is of another, and measuring the change between two values. Just type your numbers and the answer appears instantly, with no button to press.
Your numbers stay private
Every calculation runs directly in your browser using plain JavaScript. Nothing you enter is sent to a server or stored anywhere, so you can use it for anything from budgeting to schoolwork with complete peace of mind — close the tab and it's gone.
Frequently asked questions
How is percentage change calculated?
We subtract the starting value from the ending value, divide by the starting value, then multiply by 100. A positive result is an increase and a negative result is a decrease.
Why does it show a dash?
A dash (—) appears when a field is empty or when a calculation would divide by zero, such as finding a percentage of zero. Fill in valid numbers and the result updates automatically.