Percentage Calculator
Every common percentage question in one place.
What do you want to work out?
What is X% of Y?
15.00% of 240.00
36.00
240.00 × 0.15 = 36.00
Common percentage conversions
| Percentage | Fraction | Decimal | Of 240 |
|---|---|---|---|
| 5% | 1/20 | 0.05 | 12.00 |
| 10% | 1/10 | 0.1 | 24.00 |
| 20% | 1/5 | 0.2 | 48.00 |
| 25% | 1/4 | 0.25 | 60.00 |
| 33.3% | 1/3 | 0.333 | 80.00 |
| 50% | 1/2 | 0.5 | 120.00 |
| 75% | 3/4 | 0.75 | 180.00 |
How the Percentage Calculator works
Four different questions get called 'percentage', and mixing them up is the usual source of errors. This calculator keeps them separate: a share of a number, one number as a share of another, change between two numbers, and reversing a percentage back to the original.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply by the percentage divided by 100. 15% of 240 is 240 × 0.15 = 36. A quick mental method: 10% is 24, half of that is 5% = 12, and 24 + 12 = 36.
How do I calculate percentage change?
Percentage change = (new − old) ÷ old × 100. From 80 to 100 is (100 − 80) ÷ 80 = 25% increase. Note the base is always the original value, which is why a 25% rise followed by a 25% fall does not return you to the start.
What is the difference between percentage and percentage points?
If a rate moves from 5% to 7%, that is a rise of 2 percentage points but a 40% increase. News reports mix these up constantly, usually in whichever direction sounds more dramatic.
How do I reverse a percentage?
Divide rather than multiply. If a price is $120 after a 20% increase, the original was 120 ÷ 1.20 = $100. Subtracting 20% from $120 gives $96, which is wrong because the 20% was applied to the smaller original figure.