What is x as a percentage of y?

Divide x by y and multiply by 100. 45 as a percentage of 60 is 45/60 = 0.75, so 75%. Getting the two the wrong way round is the most common error here and gives 133.3%.

Why is my answer above 100%?

Because the first number is larger than the second. That is a valid answer whenever it is meant, such as revenue against target, and a sign the inputs are reversed whenever it is not.

Math & Statisticspercentage

What Percent of X is Y Calculator

What percentage one number is of another. The most common percentage question and the one phrased most awkwardly.

Also called: what percentage is x of y, percent of total calculator.

Percentage

25%

45 is 25% of 180.

How this is calculated

Method and background

How this is calculated

Divide the part by the whole and multiply by a hundred. The only trap is which number is the whole; the phrasing "x is what percent of y" always puts the whole after "of".

percent = part / whole * 100

a: The part
b: The whole: the number after "of"

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

45 of 180 is 25%

This number: 45
Is what percent of: 180

Percentage25%

arithmetic identity

Open this example

the part can exceed the whole

This number: 200
Is what percent of: 180

Percentage111.11%

boundary

Open this example

a zero whole is undefined

This number: 45
Is what percent of: 0

Percentage0%

degenerate case: guarded division

Open this example

Frequently asked questions

What is x as a percentage of y?: Divide x by y and multiply by 100. 45 as a percentage of 60 is 45/60 = 0.75, so 75%. Getting the two the wrong way round is the most common error here and gives 133.3%.
Why is my answer above 100%?: Because the first number is larger than the second. That is a valid answer whenever it is meant, such as revenue against target, and a sign the inputs are reversed whenever it is not.