CalculatorPercentage Calculator
% of is
is what % of ?
Change from to
increased by %
with % off
Five everyday percentage questions
| Question | Formula | Example |
|---|---|---|
| What is 15% of 80? | 80 × 15 ÷ 100 | 12 |
| 30 is what % of 120? | 30 ÷ 120 × 100 | 25% |
| Change from 80 to 100 | (100 − 80) ÷ 80 × 100 | +25% |
| 100 increased by 10% | 100 × 1.10 | 110 |
| 100 with 10% off | 100 × 0.90 | 90 (you save 10) |
Type numbers into any row and the answer appears right away. Click an answer to copy it.
Percent change vs. percentage points
If an interest rate goes from 2% to 3%, it rises by 1 percentage point but by 50 percent (because 1 is half of 2). News reports often mix these up. The "change" row above gives the percent change.
Why +10% then −10% doesn't bring you back
100 increased by 10% is 110. But 110 with 10% off is 99, not 100, because the second 10% is taken from a bigger number. To undo a 10% increase, you need to take off about 9.09%.
FAQ
How do I find a sale price?
Use the "% off" row. A jacket priced 50 with 30% off is 50 with 30% off = 35.
How do I turn a test score into a percentage?
Use the second row. 42 correct answers out of 50 is 42 ÷ 50 × 100 = 84%.
Can I enter negative numbers or decimals?
Yes, for example −12.5. The change row also works when values fall below zero.
Related guide
- How to Calculate Percentages: Simple MethodsLearn the three core percentage calculations, how to reverse a percentage, and the difference between percent and percentage points, with worked examples.
- Discount Guide: Sale Prices and Stacked DealsWork out sale prices, check a price tag, find the original price, and see why 20% off then 10% off is not 30% off. Worked examples included.
- Percent Change: Increase, Decrease and GrowthHow to calculate percent increase and decrease, why +10% then -10% does not get you back to the start, and how to read growth rates in charts.
- Ratios and Proportions: Recipes, Maps and Fair SplitsSimplify ratios, solve proportions by cross-multiplication, scale a recipe, read a map scale, turn ratios into percentages and split amounts 3:2.