Percentage calculator
To find X% of Y, multiply Y by X and divide by 100 (20% of 150 = 30). The four calculators below also find what percent one number is of another, the percentage change between two numbers, and a number increased or decreased by a percent.
- 🔒 Runs on your device
- ⤒ 0 bytes uploaded
- 📴 Works offline
- ✓ Free, no sign-up, no watermark
How to use Percentage Calculator
- Pick the question you have: X% of Y, X is what % of Y, change from X to Y, or increase/decrease by X%.
- Type your two numbers in that box.
- Read the answer, the formula and the worked steps underneath, updated as you type.
About Percentage Calculator
Percent means "per hundred", so 20% is 20/100 = 0.2. Every percentage question is one of three unknowns in part = percent ÷ 100 × whole: the calculator solves for each of them, and for the change between two values.
Is it private?
Yes. Percentage Calculator runs entirely in your web browser. What you type is never sent to Nolo or anyone else, and the page cannot send it anywhere: its security policy only allows it to talk to nolotools.com, which has no place to receive data. Nothing is stored either: close the page and it is gone. How Nolo works.
Questions and answers
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. 15% of 80 = 80 × 15 ÷ 100 = 12.
How do I work out what percent one number is of another?
Divide the part by the whole and multiply by 100. 30 out of 150 = 30 ÷ 150 × 100 = 20%.
How do I calculate percentage change?
Subtract the old value from the new one, divide by the old value and multiply by 100. From 50 to 75: (75 − 50) ÷ 50 × 100 = +50%.
Why is a 50% rise followed by a 50% fall not back to the start?
Because each percentage is of a different base. 100 + 50% = 150, and 150 − 50% = 75. The calculator shows the reverse change for this reason.
Are my numbers sent anywhere?
No. Everything is calculated in your browser with JavaScript. Nothing you type is uploaded, stored on a server or tracked, and the calculator works offline once the page has loaded.