➗ Decimal to Fraction Converter
By ToolNimba Math Team · Updated 2026-06-19
Type any terminating decimal, with or without a whole-number part.
Enter a fraction to see its decimal value and lowest terms.
This decimal to fraction converter turns a decimal such as 0.75 into a clean fraction in lowest terms (3/4), and shows the mixed number form for values above one. Type a decimal and read off the simplified fraction straight away. Switch to the reverse mode to enter a fraction and see its decimal value instead. It is handy for homework, recipes, woodworking measurements, and anywhere a fraction reads more clearly than a long decimal.
What is the Decimal to Fraction Converter?
A decimal and a fraction are two ways of writing the same number. A terminating decimal (one that ends, like 0.625) can always be written as a fraction whose denominator is a power of ten. The digit positions after the point tell you the denominator: one decimal place means tenths, two means hundredths, three means thousandths, and so on. So 0.625 starts life as 625/1000 before you simplify it.
Simplifying, also called reducing to lowest terms, means dividing the top and bottom by their greatest common divisor (GCD). For 625/1000 the GCD is 125, so dividing both by 125 gives 5/8. The value never changes when you do this, only the way it is written, because 625 divided by 1000 and 5 divided by 8 are both exactly 0.625. This tool computes the GCD with the Euclidean algorithm and divides through automatically.
When the decimal is greater than one, the same fraction can be shown as a mixed number: a whole part plus a proper fraction. For example 2.4 becomes 24/10, which reduces to 12/5, and 12/5 is the same as the mixed number 2 and 2/5. The reverse direction simply divides the numerator by the denominator, so 3/8 becomes 0.375. This converter treats the decimal you type as a terminating value, so it does not try to detect an infinitely repeating pattern.
When to use it
- Turning a measurement like 0.375 inch into the fraction 3/8 inch for a tape measure or ruler.
- Checking a maths homework answer by converting a decimal back into its simplest fraction.
- Scaling a recipe where 0.25 cup is easier to measure as 1/4 cup.
- Reading an engineering or woodworking drawing that mixes decimal and fractional dimensions.
How to use the Decimal to Fraction Converter
- Make sure the Decimal to fraction mode is selected.
- Type the decimal value you want to convert (for example 0.75).
- Read the fraction in lowest terms, the mixed number form, and the decimal back.
- To go the other way, click Fraction to decimal and enter a numerator and denominator.
Formula & method
Worked examples
Convert 0.625 to a fraction in lowest terms.
- 0.625 has 3 decimal places, so multiply and divide by 10 to the power 3 (1000)
- This gives 625/1000
- Find the greatest common divisor of 625 and 1000, which is 125
- Divide both by 125: 625 ÷ 125 = 5 and 1000 ÷ 125 = 8
Result: 0.625 = 5/8
Convert 2.4 to a fraction and a mixed number.
- 2.4 has 1 decimal place, so write it as 24/10
- The greatest common divisor of 24 and 10 is 2
- Divide both by 2: 24 ÷ 2 = 12 and 10 ÷ 2 = 5, giving 12/5
- 12 divided by 5 is 2 with a remainder of 2, so the mixed number is 2 and 2/5
Result: 2.4 = 12/5 = 2 2/5
Common decimals and their fractions in lowest terms
| Decimal | Fraction | Mixed number |
|---|---|---|
| 0.1 | 1/10 | 1/10 |
| 0.25 | 1/4 | 1/4 |
| 0.5 | 1/2 | 1/2 |
| 0.75 | 3/4 | 3/4 |
| 0.125 | 1/8 | 1/8 |
| 0.375 | 3/8 | 3/8 |
| 1.5 | 3/2 | 1 1/2 |
| 2.4 | 12/5 | 2 2/5 |
Common mistakes to avoid
- Forgetting to simplify. Writing 0.5 as 5/10 is correct but not in lowest terms. Always divide the top and bottom by their greatest common divisor, so 5/10 becomes 1/2.
- Miscounting the decimal places. The number of digits after the point sets the denominator. 0.05 has two places, so it is 5/100 (which reduces to 1/20), not 5/10.
- Treating a repeating decimal as terminating. A value like 0.3333 typed in here is treated as the terminating decimal 3333/10000, not as the exact one third. For true repeating decimals the exact fraction needs a different method.
- Rounding before converting. If you round 0.666 to 0.67 first, you get 67/100 instead of a value close to 2/3. Convert the most precise decimal you have, then simplify.
Glossary
- Numerator
- The top number of a fraction, counting how many parts you have.
- Denominator
- The bottom number of a fraction, showing how many equal parts make a whole.
- Lowest terms
- A fraction reduced as far as possible, where the numerator and denominator share no common factor other than one.
- Greatest common divisor
- The largest whole number that divides both the numerator and denominator exactly. Dividing by it simplifies the fraction.
- Mixed number
- A whole number written together with a proper fraction, such as 2 and 2/5, for values greater than one.
- Terminating decimal
- A decimal that ends after a finite number of digits, such as 0.625, as opposed to one that repeats forever.
Frequently asked questions
How do I convert a decimal to a fraction?
Count the digits after the decimal point. That many digits means a denominator of ten, a hundred, a thousand and so on. Write the decimal over that power of ten, then divide the top and bottom by their greatest common divisor to reach lowest terms. For example 0.75 becomes 75/100, which simplifies to 3/4.
What is 0.75 as a fraction?
0.75 is 75/100, and dividing both numbers by 25 gives 3/4. So 0.75 equals three quarters.
What is a fraction in lowest terms?
A fraction is in lowest terms when the numerator and denominator have no common factor other than one, so it cannot be reduced further. For instance 5/8 is in lowest terms, while 50/80 is not because both can be divided by 10.
How do I write a decimal greater than one as a mixed number?
Convert it to an improper fraction first, then divide the numerator by the denominator. The quotient is the whole part and the remainder over the denominator is the fraction. So 2.4 is 12/5, and 12 divided by 5 is 2 remainder 2, giving the mixed number 2 and 2/5.
Can this tool handle repeating decimals?
It treats whatever you type as a terminating decimal. If you enter 0.3333 it returns 3333/10000, which is very close to but not exactly one third. Converting a truly repeating decimal to its exact fraction needs a separate algebraic method.
How do I convert a fraction back to a decimal?
Divide the numerator by the denominator. Switch this tool to the Fraction to decimal mode and enter the two numbers, or do it by hand: 3 divided by 8 is 0.375.