Transparent method
The formula
Worked example
Example inputs
How to interpret the result
A percentage relates a part to a whole, and both figures have to describe the same underlying unit for the result to mean anything real. Asking what percentage 40 apples is of 200 total pieces of fruit is a legitimate question, while asking what percentage 40 apples is of $200 mixes two unrelated units into a number that looks valid but describes nothing.
Before you rely on it
What to check
Confirm both the part and the whole are measuring the same kind of thing before trusting the percentage the calculation returns.
The common error
Where people go wrong with percentage calculator
Running a percentage calculation across two figures that measure different units. The arithmetic still produces a number, but it doesn't describe any real relationship when the two inputs aren't comparable in the first place.
Sensitivity evidence
How part changes the percentage
| Part | Percentage | Remainder |
|---|---|---|
| 20 | 10.0% | 180 |
| 23 | 11.5% | 177 |
| 25worked example | 12.5% | 175 |
| 28 | 14.0% | 172 |
| 30 | 15.0% | 170 |
Every input, tested
Which input moves the percentage most
| Input | Tested from | To | Percentage at each end | Swing |
|---|---|---|---|---|
| Whole | 180 | 220 | 13.9% to 11.4% | 2.5% (20%) |
| Part | 23 | 28 | 11.5% to 14.0% | 2.5% (20%) |
Two variables at once
Percentage by part and whole
| Part \ Whole | 160 | 200 | 240 |
|---|---|---|---|
| 20 | 12.5% | 10.0% | 8.3% |
| 23 | 14.4% | 11.5% | 9.6% |
| 25 | 15.6% | 12.5% | 10.4% |
| 28 | 17.5% | 14.0% | 11.7% |
| 30 | 18.8% | 15.0% | 12.5% |
Step by step
The worked example, input by input
| Input | Value used |
|---|---|
| Part | 25 |
| Whole | 200 |
| Percentage | 12.5% |
| Remainder | 175 |
Where the inputs come from
Part is the number you are measuring, and whole is the total it belongs to. For example, 25 out of 200. This tool answers what percent one number is of another, while other pages find a percent of a number or a change between two values. Use the same units for both, and make sure the whole is the right base: a percentage of the wrong total gives a misleading answer.
When the result stops applying
Percentage points differ from percent: a rise from 4% to 6% is two percentage points, or a 50% increase. Rounding can hide small differences in small samples.
What to compare it with
See how two values change on the percentage change calculator, and apply a discount on the discount page. The test score percentage and grade target calculators use the same idea. The fraction and ratio tools in the math category cover related conversions.
People also ask
Frequently asked questions
How do I calculate what percent one number is of another?
Divide the part by the whole and multiply by 100. For 25 out of 200, 25 divided by 200 is 0.125, or 12.5%.
What is the difference between percent and percentage points?
A move from 4% to 6% is two percentage points but a 50% increase in the rate. Percentage points describe the arithmetic gap.
Can a percentage be more than 100?
Yes, when the part is larger than the whole you compare it with, such as sales this year at 120% of last year's.