Percentage Calculators
Work out a percentage of a number, percentage change, and reverse a percentage back to its original value.
A percentage is a number out of 100, so most percentage questions are one of a small set of calculations: a percentage of a value, one value as a percentage of another, a change from an old value to a new one, or the gap between two values with no starting point.
The calculators below each answer one of those questions and show the formula with the result. If you are not sure which one you need, the question list below matches common wordings to the right tool.
Calculators in this category
Which calculator do I need?
- What is 15% of 240? The Percentage Calculator also answers "what percentage is 36 of 240?" and reverses a percentage back to the original value.
- What is 240 plus 15%? The Percentage Increase Calculator applies a rise such as a pay increase or a price rise.
- What is 240 minus 15%? The Percentage Decrease Calculator applies a reduction; for prices in a sale, the Discount Calculator also shows the saving.
- By what percentage did a value go up or down? The Percentage Change Calculator measures the change from an original value, with a sign for the direction.
- How far apart are two values, with neither as the starting point? The Percentage Difference Calculator compares two values against their average, so the order does not matter.
Good to know
A change from 80 to 100 is a 25% increase, but a change from 100 to 80 is a 20% decrease. The base is always the starting value, which is why the two are not equal.
Percentage points and percent are different: a rate rising from 4% to 5% has risen by 1 percentage point, which is a 25% increase in the rate. The percentages guide covers this and successive percentage changes.
Background reading
- Percentages The five everyday percentage calculations, percentage points versus percent, successive changes, and why reversing a percentage is not the same as applying it backwards.