Fraction ⇄ Decimal ⇄ Percent Converter
Last updated: October 7, 2026
Convert in any direction between fractions, decimals, and percentages, instantly.
Type a fraction (1/2), mixed number (2 1/2), decimal (0.375), or percent (37.5%), get the same value expressed in all three forms. No sign-up, no popups, no ads on top of the answer.
Examples: 1/2 → 0.5 = 50% · 0.375 → 3/8 = 37.5% · 2 1/4 → 2.25 = 225%
How fraction, decimal, and percent conversion works
A fraction, a decimal, and a percent are three ways to write the same number. One half is 1/2, 0.5, and 50%. Converting among them is arithmetic, not a new quantity. A fraction becomes a decimal when you divide the numerator by the denominator: 3/8 = 3 ÷ 8 = 0.375. A decimal becomes a percent when you multiply by 100: 0.375 × 100 = 37.5%. A percent becomes a decimal when you divide by 100, which is what this tool does when the input ends with a percent sign: 37.5% is stored as 0.375, then shown again as a percent and as a fraction.
Mixed numbers are a whole number plus a fraction. Type a space between them: 2 1/2 means 2 + 1/2 = 2.5. The decimal result is rounded for display to six places, and the percent result to four places, so a clean fraction may show as 0.333333 and 33.3333% even though one third repeats forever.
Going from a decimal back to a fraction is the step that needs a search. The converter looks for a numerator and a denominator, with the denominator up to 10,000, that sits close to the fractional part, then reduces the fraction by their greatest common divisor. Exact values such as 0.375 land on 3/8. A shortened repeating decimal such as 0.333 lands near 333/1000, which is not the same as 1/3. If you know the exact fraction, type the fraction.
Worked examples
Example 1: A common kitchen fraction
Enter 3/8. Decimal 0.375. Percent 37.5%. That is the same relationship you use when a recipe calls for 3/8 teaspoon and a scale or a metric spoon needs a decimal.
Example 2: A mixed number above one
Enter 2 1/4. The value is 2.25, and the percent is 225%. Percents are allowed to exceed 100 whenever the number is greater than 1. Two and a quarter dollars is 225% of one dollar. That is correct, and it is different from "a 225% discount," which is not what this tool is computing.
Example 3: Why 0.333 is not one third
Enter 1/3 and you get a repeating decimal displayed to six places, about 0.333333, and a percent near 33.3333%, with the fraction shown as 1/3 because you typed the exact value. Enter 0.333 instead and the fraction search sees three hundred thirty-three thousandths. For grades, money, and recipes, type the fraction when you have it, or type enough decimal places that the difference does not matter for the decision.
Example 4: A tape measure and a spreadsheet
A mark at 7/16 inch is 7 ÷ 16 = 0.4375 inches, or 43.75% of one inch. Five feet plus 7/16 inch is 5 × 12 + 0.4375 = 60.4375 inches. Convert that length onward in the Length Converter if the drawing is in centimeters. Keep the fraction on the tape and the decimal in the spreadsheet so rounding does not walk you off the mark.
Example 5: A percent that needs to become a fraction of a cup
Seventy percent of 3/4 cup is 0.70 × 0.75 = 0.525 cups. The converter will show 0.525 as a decimal, a percent, and a nearby fraction. For baking, 0.525 cups is an awkward volume. The Recipe Scaler is built to multiply a whole ingredient list, and the Cooking Measurement Converter is the better next step if you can switch that ingredient to grams.
When to use this
Use it whenever the same value has to be written in the form a form, a recipe, or a drawing expects. Teachers use it to show that 4/5, 0.8, and 80% are one row in a grade book. Shoppers use it to see that 1/4 off is 25% off and that the remaining price is 3/4 of the original, which you can finish in the Percent Off Calculator. Carpenters use it to turn sixteenths into decimals before a cut list goes into a spreadsheet. The Percent Change Calculator is the follow-up when you have two different numbers and want the percent between them, rather than three names for one number.
Common mistakes
- Leaving the percent sign off. The number 37.5 is thirty-seven and a half, which is 3750%. The number 37.5% is 0.375. The sign chooses the meaning.
- Dropping the space in a mixed number. 2 1/2 is 2.5. The text 21/2 is twenty-one halves, which is 10.5.
- Typing a fancy fraction glyph. Use a slash, as in 1/2. A single-character ½ is a different symbol and may not parse.
- Confusing a ratio with a fraction. 3:4 is a comparison of two parts. 3/4 is one number. The Ratio Calculator handles the colon form.
- Rounding, then converting, then rounding again. Convert from the most exact form you have, and round once at the end for the tool that will use the number.
Limitations
The parser accepts a plain fraction, a mixed number with one space, a decimal, or a percent. It does not evaluate stacked expressions such as 1/2/3, and it does not do algebra. The fraction it prints for a messy decimal is a close match with a modest denominator, which may not be the fraction a textbook uses for a repeating pattern. Negative values are accepted, with the sign kept on the result. There is no unit attached: 0.5 may be half a cup, half a dollar, or 50% of a grade, and the page cannot tell which.
FAQ
Is 100% equal to 1?
Yes. One hundred percent, the decimal 1, and the fraction 1/1 are the same value. Fifty percent is 0.5 and 1/2. Two hundred percent is 2.
Why will the fraction box not show 1/3 when I type 0.33?
Because 0.33 is exactly 33/100, which reduces to 33/100. One third is the repeating decimal 0.333… with no end. Type 1/3 if that is the value you mean. Type more threes only if you are approximating.
How do I turn a discount percent into the fraction I still pay?
Subtract the discount from 100 and write that over 100. Twenty-five percent off leaves 75/100, which reduces to 3/4. You pay three-quarters of the original price.
Can the percent be larger than 100?
Yes, whenever the number is larger than 1. A mixed number such as 2 1/2 is 250%. That display is the conversion, not a claim that something increased by 250%.
What should I type for a repeating percent like 66.6%?
If the source is two-thirds, type 2/3. If the source really is 66.6% and not 66.666…%, type 66.6% so the trailing precision matches the document you were given.
Practical tips
On a tape, stay in the fraction the tape is marked in, usually eighths or sixteenths, until you must enter a decimal. Convert 7/16 once, use 0.4375, and do not replace it with 0.44 halfway through a layout. In the kitchen, prefer grams for anything you will scale; cups and spoons hide packing differences that a percent conversion cannot fix. Cooking measurement myths is the companion if a cup of flour is the thing you are about to treat as exact. Half, double, and a third of common cup and tablespoon amounts are on the recipe halving, doubling, and thirding chart. This page rewrites one number. It does not scale the recipe.
For schoolwork, write all three forms on the same line so a later step can use whichever one fits. Multiply and divide with the fraction or the full decimal, then convert to a percent at the end if the question asks for a percent. That order avoids turning 1/3 into 33% too early and then drifting off the exact answer.
When a form rejects fractions, convert here and paste the decimal. When a form rejects decimals, paste the fraction the tool prints and simplify further by hand if the form expects a denominator of 4, 8, or 16 only.