# Percentage Calculator

> Work out a percentage of a number, what percentage one number is of another, and increases or decreases.

Canonical: https://host-tools.com/tools/percentage-calculator/

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## What does this tool do?

Answers the five percentage questions people actually ask, one screen, each with the fields named
after what they hold:

| Question | What you type |
| --- | --- |
| What is A % of B? | the percentage and the number |
| A is what percentage of B? | the part and the total |
| What is the change from A to B? | the two values, in order |
| A increased by B %? | the value and the percentage |
| A decreased by B %? | the value and the percentage |

## The formula comes back with your numbers

Every result shows the arithmetic it used — `(15 × 240) ÷ 100` — instead of only the answer. That is
what makes the result checkable, and it is also how you notice that you picked the wrong question.

## Percentages that do not exist

Dividing by zero has no percentage answer, and this tool says so rather than showing `Infinity`:
“the change from zero” and “what percentage of nothing” are rejected with a sentence that says why.
Results are rounded to six decimals, which removes the floating-point dust — `3 % of 0.1` is
`0.003`, not `0.0029999999999999996`.

## Keep in mind

Everything runs in your browser: the numbers never leave your machine.