DocomintPercentage Calculator
Find X% of a number, calculate percentage change, or work out what percent one number is of another.
Percentage questions come up in three different shapes that people often mix up: "what is X% of Y" (a discount, a tip, a tax), "what's the percentage change from A to B" (a price increase, a stat swinging quarter to quarter), and "X is what percent of Y" (test scores, market share). This bundles all three into one tool so you don't have to remember which formula goes with which question.
Example: A shirt priced at $80 goes on sale for $104 — wait, that's an increase. Using the percentage-change mode on a $80 → $104 jump returns +30%, useful for checking a reported price hike against the actual before/after numbers rather than trusting a rounded headline figure.
How it works
- Pick which of the three percentage calculations you need
- Enter the numbers involved
- The result appears instantly, calculated on your device
Frequently asked questions
How do I calculate X% of a number?
Divide the percentage by 100 to get a decimal, then multiply by the number. 15% of 240 is (15 ÷ 100) × 240 = 36.
What's the difference between percentage change and percentage points?
Percentage change is relative: going from 20% to 25% is a 5-percentage-point increase, but a 25% percentage change (5 is 25% of 20). News headlines often blur the two — always check which one a reported figure actually means.
Is my numbers uploaded anywhere?
No — Percentage Calculator runs entirely in your browser using JavaScript/WebAssembly. Your numbers is never sent to a server.