Percentage Calculator

This page answers what is X% of Y, and only that. Type the percentage in the first box and the number in the second. The result is Y × X ÷ 100, so the defaults give 15% of 200 = 30.

The other two everyday percentage questions have their own calculators on this site:

• 30 is what percent of 200? Use the What Percentage Is X of Y calculator.
• What's the percent change from 80 to 100? Use the Percentage Increase / Decrease calculator.

A useful shortcut: X% of Y always equals Y% of X. 8% of 50 is awkward, but 50% of 8 is obviously 4, and the calculator gives 4 either way.

When the number you're taking a percentage of is itself a percentage, two different things get called "percent".

• An interest rate going from 4% to 5% rose by 1 percentage point. As a relative change it rose by 25%, because 25% of 4 is 1.
• A rate of 5% that "rises by 10%" ends at 5.5%, not 15%. Enter 10% of 5 and you get the 0.5 it actually rose by.
• A party polling 40% that gains 6 points has grown its share by 15%, since 15% of 40 is 6.

Headlines mix these up all the time. When you read "up 10%", check which one is meant before you do anything with the figure.

Percentages of subgroups multiply. Say 15% of your customers answered a survey and 20% of those who answered reported a problem. That's 20% of 15, which the calculator gives as 3, so 3% of all customers, not 20%.

The same logic applies to anything filtered twice: 40% of an email list opens a message and 15% of the openers click, so 15% of 40 = 6% of the whole list clicked.

The result shows up to two decimal places and drops trailing zeros. 12.5% of 37 is exactly 4.625, displayed as 4.63. If the answer stands for whole things, such as people or items, round it yourself in whichever direction makes sense: you can't invite 4.63 guests.

Rounding can also hide a small error in what you typed. 33.333% of 90 is 29.9997, which displays as 30. If you really mean one third, dividing by 3 is exact, and 33.333% isn't.