Decimal to Percent Calculator

A percent is a number that you get by multiplying a decimal number by 100. If you enter 0.25 into the Decimal field, it will give you 25%. If you enter 25 into the Percentage field, it will give you 0.25. This simple relationship is at the core of all conversions and is used in a variety of fields such as money, fractions, and probability.

Why is multiplying by 100 useful?

"Percent" means "per one hundred units." So converting a decimal to a percent actually involves finding out how many hundreds of units that decimal represents.

Multiplying a number by 100 and then dividing it by 100 does not change its value because 100 divided by 100 is equal to one. This is because you are simply rewriting the number so that the denominator has the form of 100, which means "one hundredth".

That means it is one quarter of a whole.

For any decimal number D, there is a simple rule:

Here's how to use this calculator.

If you enter a decimal number in the first column, you can check the percentage. If you enter a percentage in the second column, you can check the decimal number. If you leave blank the field that you want to calculate, the calculator will automatically fill out the result.

The system accepts both negative numbers and values greater than 1.0, so a decimal of 2.5 will return the value 250% and a decimal of -0.15 will return the value -15%. When you open an additional view, you can see the value in different formats such as reduced fraction, thousandths or basis points, along with a chart that represents it as part of 100.

A simple method for two decimal places:

If you want to do this conversion in your head, there is a simpler method. To convert a decimal number into a percentage, simply move the decimal point two places to the right and add the percent sign.

So .35 becomes 35%, and .6 becomes 60%. To convert in the opposite direction, move the decimal two places to the left and drop the percent sign; so 45% becomes .45.

Common conversions worth memorizing.

There are some commonly used conversions that will make it easier for you to do everyday calculations in your head.

Decimals, parts per thousand and basis points

The percentage is not the only unit of measure based on this concept. Parts per thousand give the proportion per 1,000 units and use a symbol that looks like a percent sign with an extra zero. So 0.25 is equal to 250 parts per thousand.

Basis points are calculated per 10,000 units and are a common way to describe interest rates and fees. One percentage point is equal to 100 basis points. The same value in 0.25 would be 2,500 basis points. When you open the view for percentages and basis points, you can see both values next to each other at the same time.

Applications of these conversions

A test score of 0.87 is equivalent to 87%. A discount of 0.20 is a 20% discount. An interest rate of 0.05, as shown in a spreadsheet, is the same as 5%, which would be advertised on a loan.

The odds can also be easily converted between the two formats so that a 0.3 chance of rain is the same as a 30% chance of rain. This conversion is used when expressing part to whole relationships.