Percents are easy to read, but most formulas need the decimal form. Interest, tax, tips, growth rates and probabilities are all calculated with the underlying multiplier, so 6.25% has to become 0.0625 before it can be used. This calculator converts any percent — whole, decimal, mixed-number or fractional — into its exact decimal, and marks repeating decimals with a bar so nothing is lost to rounding.
How to use the percent to decimal calculator
- Type the percent, with or without the % sign. Examples:
45%,0.75,150%,12 1/2%,1/4%. - The decimal appears on the tape, along with the equivalent fraction.
- For decimal percents, the diagram shows the point moving two places to the left. For fractional percents, the steps show the fraction arithmetic and any repeating block.
Percent to decimal formula
Dividing by 100 moves the decimal point two places to the left. When there aren’t enough digits in front of the point, add leading zeros: 7% → 0.07, and 0.3% → 0.003.
For a fractional percent such as 12½%, convert the fraction first: 12½ = 25/2, and 25/2 ÷ 100 = 25/200 = 1/8 = 0.125.
Worked example: an interest rate
A savings account pays 6.25% per year. To find one year’s interest on $2,400, you need the rate as a decimal.
Divide by 100: 6.25 ÷ 100 = 0.0625
Use it in the formula: 2,400 × 0.0625 = $150 of interest
Fraction check: 6.25/100 = 625/10,000 = 1/16, and 1 ÷ 16 = 0.0625
Common percents as decimals
| Percent | Decimal | Fraction |
|---|---|---|
| 0.1% | 0.001 | 1/1,000 |
| 1% | 0.01 | 1/100 |
| 6.25% | 0.0625 | 1/16 |
| 12½% | 0.125 | 1/8 |
| 33⅓% | 0.3̅ | 1/3 |
| 66⅔% | 0.6̅ | 2/3 |
| 87.5% | 0.875 | 7/8 |
| 150% | 1.5 | 3/2 |
Fractional percents and repeating decimals
Older textbooks, bond prices and recipe scaling still use fractional percents like 33⅓%, 16⅔% and 62½%. They exist precisely because the decimal versions don’t terminate: 33⅓% is exactly one third, while 33.33% is only close to it. The calculator keeps these values exact. When the decimal repeats, a bar (called a vinculum) marks the repeating block — 0.1̅6̅ would mean 0.161616…, while 0.16̅ means 0.1666….
Mistakes to avoid
- Forgetting the zeros for small percents. 0.5% is 0.005, not 0.5. A half percent is a half of one hundredth.
- Dividing twice. If a value is already a decimal (0.08), don’t divide it by 100 again. Check whether the number you were given had a percent sign.
- Using rounded repeating decimals in long calculations. For 33⅓%, multiplying by 0.33 instead of 1/3 makes a result about 1% too small. Keep the fraction or several extra digits until the end.
- Thinking percents can’t exceed 100. 125% is 1.25 — a quantity plus another quarter of it.
Where you need the decimal form
- Calculating simple interest or loan payments, where the rate is always a decimal in the formula.
- Working out sales tax: an 8.25% tax means multiplying the price by 0.0825.
- Probability and statistics, where 35% chance is written as P = 0.35.
- Spreadsheets: in Excel or Google Sheets,
=B2*6.25%and=B2*0.0625give the same answer because the % sign tells the software to divide by 100.
To reverse the conversion, use the decimal to percent calculator. If you need the percent as a simplified fraction rather than a decimal, try the percent to fraction calculator.
Frequently asked questions
How do you convert a percent to a decimal?
Drop the percent sign and divide by 100, which moves the decimal point two places to the left. 6.25% becomes 0.0625 and 45% becomes 0.45.
What is 0.5% as a decimal?
0.5 ÷ 100 = 0.005. A common mistake is to write 0.5, which is actually 50%. Small percents need extra zeros after the decimal point.
How do I convert a fractional percent like 33 1/3%?
Turn the mixed number into an improper fraction (100/3), then divide by 100 to get 1/3. As a decimal that is 0.333…, a repeating decimal written with a bar over the 3.
Why do formulas need the decimal form of a percent?
A percent is shorthand for a number divided by 100. Formulas for interest, tax and growth use the actual multiplier, so 4.5% must enter the formula as 0.045. Typing 4.5 would make the result 100 times too large.
What is 250% as a decimal?
250 ÷ 100 = 2.5. Percents above 100 always give decimals greater than 1.