About this tool
The Percentage Calculator is a free online tool that solves the four most common percentage problems in one place: what is X% of Y, X is what percent of Y, percentage change from A to B, and reverse percentage.
How it works
1
Choose your percentage question
Pick the format that matches what you need: X% of Y, X is what % of Y, or percentage change from A to B.
2
Enter your numbers
Type the values into the input fields.
3
Read the answer instantly
Click the equals button and the result appears below with the exact formula used.
Frequently Asked Questions
What is the difference between percentage change and percentage point? v
Percentage change measures relative change: 4% to 6% is a 50% increase. Percentage points measure absolute difference: 4% to 6% is a 2-point increase.
How do I calculate a discount? v
Use the 'X is what % of Y' row. Enter the discount amount as X and the original price as Y.
Why is a 50% loss not recovered by a 50% gain? v
Because they apply to different bases. $100 falls 50% to $50. A 50% gain on $50 brings you to $75, not $100.
Is this tool free and private? v
Yes. Completely free, no signup, no tracking.
Can I use this for business calculations like markup and margin? v
Yes for markup. Markup = (selling price - cost) / cost x 100. For margin, use a dedicated margin calculator.
How precise are the results? v
Standard JavaScript floating-point precision (up to 15 significant digits).