Percentage Calculator
What is X% of Y, percentage change, and percentage difference — all in one place.
Three common percentage questions in one tool: what is X% of Y, what percent is X of Y, and percentage increase or decrease between two numbers.
Not sure which formula you need? Read how to calculate percentage, covering all three with worked examples.
Which calculator to use
| Your question | Use | Example |
|---|---|---|
| How much is 25% off $80? | What is X% of Y | 25% of 80 = 20, so you pay $60 |
| I got 18 of 24 questions right — what percent is that? | X is what percent of Y | 18 ÷ 24 = 75% |
| My salary went from $52,000 to $55,120 — what's the raise? | Percentage change | +6% |
| A price dropped from $60 to $45 — by how much? | Percentage change | −25% |
Working backward: finding the original number
The three calculators above go forward from a starting number. To reverse a percentage — for example, to find a price before a discount or before tax — divide instead of multiplying:
- Before a discount: original = sale price ÷ (1 − discount%). $60 after 25% off was 60 ÷ 0.75 = $80.
- Before an increase: original = new value ÷ (1 + increase%). A $55,120 salary after a 6% raise was 55,120 ÷ 1.06 = $52,000.
Two common percentage mistakes
Percent vs. percentage points. A mortgage rate moving from 4% to 5% is a rise of 1 percentage point, but a 25% increase in the rate. News reports often mix these up.
Gains and losses aren't symmetric. A 50% drop followed by a 50% rise leaves you 25% below where you started ($100 → $50 → $75), because the second percentage is taken from a smaller number.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100, then multiply by the number. For example, 20% of 50 is (20/100) × 50 = 10.
What is percentage change vs. percentage difference?
Percentage change (used here) compares a "before" and "after" value and can be positive (increase) or negative (decrease). It always uses the starting value as the base.
What is the difference between percent and percentage points?
Percentage points measure the plain difference between two percentages; percent measures the relative change. An interest rate rising from 4% to 5% went up 1 percentage point, but that is a 25% increase in the rate itself.
Why doesn't a 50% gain undo a 50% loss?
Each percentage is taken from a different starting value. $100 that drops 50% becomes $50, and a 50% gain on $50 only gets you to $75. To get back to $100 you need a 100% gain.
How do I find the original price before a discount?
Divide the sale price by (1 − discount ÷ 100). If something costs $60 after 25% off, the original price was 60 ÷ 0.75 = $80.
Can a percentage be more than 100%?
Yes. 150% of 40 is 60, and a value that grows from 50 to 125 has increased by 150%. Percentages above 100 simply mean more than the whole.