About Percentage Calculator
The Percentage Calculator answers the three percentage questions everyone runs into: What is X% of Y? What percentage of Y is X? And what is the percentage change from one number to another? Type your numbers and get the answer instantly — no formulas to remember.
It's handy for computing discounts and sales tax, working out tips, tracking value changes in reports, calculating grade scores or figuring commission. Each mode shows the result live as you type, so you can adjust numbers and compare scenarios quickly.
How to Use the Percentage Calculator
- Pick the calculation type: percentage of a number, ratio as a percentage, or percentage change.
- Enter your two numbers.
- Read the result, updated instantly as you type.
Features
- Three modes: % of a number, X is what % of Y, and % change
- Live results as you type
- Handles decimals and negative values
- No formulas to memorize
Frequently Asked Questions
How do I calculate a percentage increase?
Subtract the old value from the new value, divide by the old value, then multiply by 100. The percentage-change mode does this for you — just enter both values.
What is 20% of 150?
30. Multiply 150 by 0.20 — or enter 20 and 150 in the '% of a number' mode.
Is the Percentage Calculator free?
Yes, the Percentage Calculator is completely free with no usage limits. No signup, no account and no installation required.
Does the calculator work on mobile?
Yes. The calculator is fully responsive and works in any modern browser on phones, tablets and desktops.