What is 15% of 100?

15% of 100 = 15

Working: 100 × 0.15 = 15

15 percent of 100 is 15.

To find a percentage of a number, convert the percentage to a decimal by dividing by 100, then multiply. Here that is 15 ÷ 100 = 0.15, and 100 × 0.15 = 15.

There is usually a faster mental route. Ten percent of 100 is 10 — just move the decimal point one place left. Half of that ten percent is 5, so 15% is 10 × 1 plus 5, giving 15.

Fifteen percent is the baseline restaurant tip in the US for adequate service, and it is awkward enough to compute that most people reach for a phone. The trick is to find ten percent, halve it, and add the two together.

One hundred is the amount that makes percentages trivial, because a percentage is literally 'per hundred' — the percentage and the answer are the same number. That is the whole origin of the notation, and working an example at 100 first is the fastest way to sanity-check any other amount.

Other percentages of 100

Percentage	Of 100
10%	10
20%	20
25%	25
30%	30
50%	50

Try another value

Percent (X)

Of value (Y)

20% of 150 is

Frequently asked questions

What is 15 percent of 100?

15% of 100 is 15. Multiply 100 by 0.15 to get the answer.

What is 15% off 100?

Taking 15% off 100 leaves 85. The discount itself is 15, so subtract that from 100 — or multiply 100 by 0.85 to get to the final price in one step.

How do you calculate a percentage of a number?

Divide the percentage by 100 to turn it into a decimal, then multiply that decimal by the number. For example 20% becomes 0.2, and 0.2 multiplied by the number gives the answer.

For any other value, use the full Percentage Calculator on BrainVert.