Loading calculator...
- Turns any decimal into a fraction in lowest terms, such as 0.625 = 5/8.
- Handles repeating decimals like 0.333… = 1/3 and 0.1666… = 1/6.
- Shows the mixed number, the percent and the nearest 1/16 and 1/64 for measuring.
- Every step is shown, from writing over a power of 10 to simplifying.
How to use the decimal to fraction calculator
Type the decimal
Enter any decimal, such as 0.625, 2.75 or −0.4.
Mark repeating digits (optional)
If the decimal repeats forever, type one cycle and choose how many digits at the end repeat. For 0.333… type 0.3 and pick 1 digit.
Read the fraction
The simplified fraction appears with the mixed number and percent.
Use the inch values
For tape measures and drill bits, read the nearest 1/16 or 1/64 value.
How to convert a decimal to a fraction
Decimals that end
1. Count the digits after the decimal point (n)
2. Write the number without the point over 10ⁿ
3. Divide top and bottom by their greatest common divisor
0.625 has 3 decimal places, so it becomes 625/1000. The GCD of 625 and 1000 is 125, giving 5/8.
Repeating decimals
Numerator = (all digits) − (digits before the repeat)
Denominator = one 9 per repeating digit, then one 0 per non-repeating decimal digit
For 0.1666…: (16 − 1) / 90 = 15/90 = 1/6. For 0.2727…: 27/99 = 3/11.
Example 1: 0.625
A decimal that ends.
- Write over 1,000 625/1000
- GCD 125
- Fraction 5/8
- Percent 62.5%
5/8 is a common inch fraction, so the nearest 1/16 value is also 5/8.
Example 2: 2.75
A decimal bigger than 1.
- Write over 100 275/100
- Simplify by 25 11/4
- Mixed number 2 3/4
Whole numbers carry straight into the mixed number.
Example 3: 0.333…
A repeating decimal.
- One repeating digit 3
- Fraction 3/9 = 1/3
Typing 0.333 without marking it as repeating gives 333/1000 instead, which is close to but not exactly one third.
Common decimals as fractions
A quick reference, including the inch fractions on a tape measure.
- 0.0625 1/16
- 0.125 1/8
- 0.1875 3/16
- 0.25 1/4
- 0.3125 5/16
- 0.375 3/8
- 0.5 1/2
- 0.625 5/8
- 0.6875 11/16
- 0.75 3/4
- 0.8125 13/16
- 0.875 7/8
Each of these has a denominator that is a power of 2, which is why they end after a few decimal places.
Where a decimal to fraction calculator helps
Homework
Check decimal to fraction questions and see the GCD step.
Measuring and woodwork
Turn a decimal inch reading such as 0.3125 into 5/16 for a tape measure.
Cooking
Convert 0.75 cup or 0.333 cup into kitchen fractions.
Engineering drawings
Switch between decimal and fractional dimensions on plans.
To add or multiply fractions, use the fraction calculator. Turn a fraction into a percent with the fraction to percent calculator, or round a decimal first with the rounding calculator.
Decimal to fraction calculator FAQ
How do you turn a decimal into a fraction?
Write the decimal over 10, 100, 1,000 and so on (one zero per decimal place), then simplify by dividing the top and bottom by their greatest common divisor.
What is 0.625 as a fraction?
0.625 = 625/1000 = 5/8.
What is 0.3125 as a fraction?
0.3125 = 3125/10000 = 5/16.
How do I convert a repeating decimal?
Type one cycle of the decimal and choose how many digits repeat. For example 0.142857142857… is 0.142857 with 6 repeating digits, which equals 1/7.
What is the nearest 1/16 value for?
Tape measures and many tools are marked in 1/16 inch. The calculator rounds your decimal to the closest 1/16 and 1/64 so you can measure it.
Can it convert negative decimals?
Yes. The sign is kept, so −0.4 becomes −2/5.