Decimal to Percent Calculator

How to convert a decimal to a percent

To turn a decimal into a percentage, multiply it by 100 and write a percent sign after the result. In practice that means moving the decimal point two places to the right.

percentage = decimal × 100 %Moving the point two places right is the same as multiplying by 100.

• 0.35 becomes 35% (0.35 × 100 = 35).
• 0.07 becomes 7%. The empty tens place needs no zero in front.
• 1.25 becomes 125%, because values above 1 give percentages above 100.
• 0.004 becomes 0.4%. The point moves two places to give 0.4.
• −0.4 becomes −40%. The sign is kept.

Why multiplying by 100 works

The word percent means "per hundred". A decimal like 0.35 states a quantity as part of one whole: 35 hundredths. Writing it as a percentage restates the same quantity as a part of one hundred, which is 35 out of 100. Because the whole is split into 100 equal slices in one case and kept as 1 in the other, converting between the two scales is a single multiplication or division by 100.

That also explains why 1 corresponds to 100%: the whole thing is one unit, and one unit is the full hundred slices. A decimal of 0.5 is half of a unit, so 50%.

Using the calculator and its rounding

Type the decimal into Decimal number and press Convert to Percentage. Negative values and values above 1 are accepted.

The percentage is rounded to four decimal places, trailing zeros are dropped and large numbers get thousands separators. For example, 0.123456789 × 100 = 12.3456789, which is displayed as 12.3457%. A decimal of 1234.5678 gives 123,456.78%, and a very small input such as 0.0000000001 rounds all the way to 0%.

Floating-point noise does not leak into the answer: 0.29 × 100 is 28.999999999999996 in raw computer arithmetic, but rounding to four decimals returns the expected 29%.

Worked example: a monthly budget

A household spreadsheet stores each spending category as a share of take-home pay. To present the figures as percentages, multiply every share by 100.

A quick sanity check is that the decimals add up to 1 and the percentages add up to 100. If your total is off, one of the shares was mistyped or misread.

Decimal to percent conversion table

Everyday examples

• Tax and interest rates. A sales tax written as 0.0825 is 8.25%, and a savings rate of 0.045 is 4.5%.
• Grades. A score of 0.875 on a test is 87.5%.
• Probability. An event with probability 0.0035 happens 0.35% of the time, about 1 in 286.
• Ratios above one. If this year's output is 2.5 times last year's, it is 250% of last year's figure, which is a 150% increase.

Percentages above 100% and below 0% are legitimate. Above 100% means more than the reference amount, and a negative percentage points to a decrease or a deficit. For percent change between two numbers, use the percentage calculator.

Converting back and common mistakes

To reverse the conversion, divide the percentage by 100, or move the point two places left: 62% becomes 0.62. The percent to decimal calculator does it for you, and the fraction to percent calculator starts from a fraction instead.

• Moving the point the wrong way or the wrong distance. 0.5 is 50%, not 5% and not 0.5%. The point always moves exactly two places to the right.
• Confusing 0.5% with 50%. The decimal 0.005 is 0.5%, while the decimal 0.5 is 50%. Count the zeros carefully.
• Mixing percent with percentage points. A rate that rises from 0.04 to 0.06 has gone up by 2 percentage points (4% to 6%), which is a 50% relative increase.
• Rounding too early. Keep the full decimal until the final step so the percentage is accurate to the digits you need.