What this calculator does
Converting a decimal to a percentage is one multiplication: multiply by 100 and add a percent sign. It works because "percent" literally means "per hundred," so a percentage is just a decimal restated on a scale of 100 rather than a scale of 1. This calculator does that conversion in both directions, decimal to percentage and percentage back to decimal.
The mistake this trips people up on is not the arithmetic, it is losing track of which direction they are converting. Multiplying when you should have divided turns 0.05 into 5,000% instead of 5%, or turns 5% into 0.0005 instead of 0.05. Keeping the "percent means per hundred" rule in mind is the simplest way to check the direction is right before trusting the answer.
The formula
To go from a decimal to a percentage, multiply the decimal by 100. To go the other way, from a percentage to a decimal, divide the percentage figure by 100. The two operations undo each other exactly.
| Term | Meaning |
|---|---|
| Decimal | A number expressed on a scale where 1 represents the whole, such as 0.375. |
| Percentage | The same value expressed on a scale of 100, such as 37.5%. |
| Percent | Latin for "per hundred," the reason multiplying or dividing by 100 converts between the two forms. |
The inputs explained
| Field | What to enter |
|---|---|
| Convert | Choose the direction of the conversion. |
| Decimal (decimal to percentage only) | The decimal value to convert to a percentage, such as 0.375. |
| Percentage (percentage to decimal only) (%) | The percentage value to convert back to a decimal, such as 37.5. |
When to use it
Reading a probability or proportion as a percentage
Statistics and probability results are often given as decimals between 0 and 1, such as a 0.62 chance of an outcome. Converting to 62% is usually the more intuitive way to communicate the same figure.
Entering a rate into a formula that expects a decimal
Interest rates, tax rates and growth rates are quoted as percentages but often need converting to a decimal before they can be used directly inside a formula, such as multiplying a price by (1 + rate).
Checking a spreadsheet formatting error
A common spreadsheet mistake is entering 37.5 into a cell already formatted as a percentage, which displays as 3750% because the software multiplies by 100 again on top of the number already being a percentage figure.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Common decimals converted to percentages
A set of frequently seen decimal values and their percentage equivalents.
Common percentages converted to decimals
A set of frequently seen percentage values and their decimal equivalents.
Questions
How do I convert a decimal to a percentage without a calculator?
Move the decimal point two places to the right and add a percent sign. 0.375 becomes 37.5%, and 0.05 becomes 5%. This is exactly the same result as multiplying by 100.
Why does converting a percentage to a decimal mean dividing by 100?
A percentage is already a "per hundred" figure, so dividing by 100 removes that scaling and returns the number to a plain fraction of 1. 37.5% divided by 100 is 0.375, the decimal it came from.
Can a percentage be greater than 100%?
Yes. Percentages above 100% simply correspond to decimals greater than 1, such as 150% being the decimal 1.5. This is common when describing growth, such as a value that more than doubled.
How is this different from the percentage calculator?
The percentage calculator answers questions like "what is X% of Y" or "Y increased by X%." This calculator does one specific, narrower conversion: restating a plain decimal as a percentage, or a percentage back as a plain decimal, with no other value involved.
For fraction-based conversions instead of decimals, see the fraction to percentage calculator. For percentage questions involving a second value, such as X% of Y, use the percentage calculator.