How to convert a decimal to a percent
Multiply the decimal by 100 and add a percent sign. That's the whole method:
Percent = decimal × 100 Multiplying by 100 is the same as moving the decimal point two places to the right, which is the quickest way to do it in your head:
- 0.25 → move the point two places right → 25%
- 0.5 → 0.50 → 50% (add a zero to make room)
- 0.035 → 3.5%
- 1.2 → 1.20 → 120%
The reason it works is that "percent" means "per hundred". A decimal expresses a value in relation to one whole, while a percentage expresses a value in relation to one hundred. Since 1 whole equals 100 hundredths, multiplying a decimal by 100 converts it to its percentage value.
What is −0.1 as a percent?
−0.1 as a percent is −10%. The method is exactly the same for negative numbers: multiply by 100 and keep the sign. −0.1 × 100 = −10, so the answer is −10%.
A negative decimal converts to a negative percentage. When the decimal represents a relative change, the negative percentage indicates a decrease: −0.1 corresponds to a 10% decrease, and −0.25 corresponds to a 25% decrease.
- −0.05 = −5%
- −0.1 = −10%
- −0.5 = −50%
- −1.25 = −125%
If you are comparing an original value with a new value and want to calculate the percentage change, use the Percentage Change Calculator.
Decimals greater than 1
A decimal of 1 is 100%, so anything above 1 becomes a percentage above 100. 1.5 is 150%, 2 is 200%, and 3.75 is 375%. Percentages over 100 are perfectly normal — they just mean more than the whole, such as a value that has more than doubled.
Very small decimals
Small decimals give percentages under 1%, which is where the point-moving method is easiest to get wrong. 0.005 is 0.5%, not 5%, and 0.0001 is 0.01%. Count the two places carefully: the point moves exactly two places every time, no matter how many zeros come first.
Decimal to percent chart
| Decimal | Percent |
|---|---|
| 0.01 | 1% |
| 0.05 | 5% |
| 0.1 | 10% |
| 0.125 | 12.5% |
| 0.2 | 20% |
| 0.25 | 25% |
| 0.333 | 33.3% |
| 0.5 | 50% |
| 0.75 | 75% |
| 0.9 | 90% |
| 1 | 100% |
| 1.25 | 125% |
| 1.5 | 150% |
| 2 | 200% |
| -0.05 | -5% |
| -0.1 | -10% |
| -0.25 | -25% |
| -0.5 | -50% |
Common mistakes
- Reading 0.5 as 0.5%. 0.5 is half, which is 50%. 0.5% is a two-hundredth — a hundred times smaller.
- Moving the point the wrong way. Decimal to percent moves it right, making the number bigger. Percent to decimal moves it left.
- Dropping the minus sign. −0.1 is −10%, not 10%. The sign survives the conversion unchanged.
Converting back: percent to decimal
Do the opposite: divide by 100, or move the decimal point two places to the left, and drop the percent sign. 25% becomes 0.25, 150% becomes 1.5, and −10% becomes −0.1.
For a specific increase or decrease from an original value, you can also use the Percentage Increase Calculator or Percentage Decrease Calculator.
Frequently asked questions
How do you convert a decimal to a percent?
Multiply the decimal by 100 and add a percent sign — or, equivalently, move the decimal point two places to the right. 0.25 becomes 25%, and 0.5 becomes 50%.
What is -0.1 as a percent?
−10%. Multiply by 100 and keep the minus sign: −0.1 × 100 = −10. When −0.1 represents a relative change, that corresponds to a 10% decrease.
What is 0.5 as a percent?
50%. 0.5 × 100 = 50. It's a common slip to read 0.5 as 0.5%, which is a hundred times smaller.
Can a percentage be more than 100%?
Yes. Any decimal greater than 1 converts to a percentage over 100%. 1.5 is 150% and 2 is 200%.
Why do I multiply by 100?
Because percent means "per hundred". A decimal counts wholes and a percentage counts hundredths, and every whole contains a hundred hundredths.