Percentage Calculator
Work out a percentage of a value, a ratio as a percentage, or an increase, a decrease and a percentage change.
Five questions cover almost every percentage problem, and mixing them up is what makes percentages feel harder than they are. Pick the one you actually have and the arithmetic is done for you, along with the absolute difference where it helps.
How it works
A percentage of a value multiplies the value by the percentage divided by one hundred: 15% of 200 is 200 x 15 / 100 = 30.
Expressing a part as a percentage of a whole divides one by the other: 30 out of 200 is 30 / 200 x 100 = 15%.
A percentage change compares a difference against the value it started from: going from 200 to 230 is (230 - 200) / 200 x 100 = 15%. The starting value is the reference, which is why a rise from 100 to 150 is +50% while the fall back from 150 to 100 is only -33.3%.
Examples
| Case | Input | Result |
|---|---|---|
| A 20% discount on a 45 price tag | Decrease 45 by 20% | 36 |
| A score of 43 out of 60 | 43 is what percent of 60 | 71.67% |
| Rent going from 950 to 1010 | Change from 950 to 1010 | +6.32% |
Frequently asked questions
Why is a 50% rise not cancelled by a 50% fall?
Each percentage is measured against a different starting point. A 50% rise from 100 gives 150, and a 50% fall from 150 removes 75, leaving 75. To return to 100 from 150 you need a fall of 33.3%.
What is the difference between percent and percentage points?
A move from 4% to 6% is a rise of two percentage points, but a rise of 50 percent, because 6 is 50% larger than 4. This tool reports the relative change in percent and gives the absolute difference alongside it.
Can I use a comma as the decimal separator?
Yes. Numbers are read using the separator of the language you are browsing in, so 12,5 is twelve and a half in French and twelve thousand five hundred is written 12 500 or 12500.
Good to know
- Results are computed with double precision floating point arithmetic, which is exact enough for everyday use but is not suitable as the accounting record of a financial transaction.