Fraction to Decimal Calculator
Enter a fraction to see it as a decimal. Repeating digits are marked in brackets, and you can round to anything from a whole number to ten places.
How to use this calculator
- Type the fraction as
5/8. Improper fractions like41/10and mixed numbers like2 3/4both work. - Leave the rounding on Exact value to see every digit, or choose the number of decimal places you need.
- Read the decimal above the supporting figures. The long-division line under the inputs shows the division being performed.
Rounding changes what is displayed as the headline, never what the fraction is. The exact value stays on screen beside it, so a figure rounded to two places can still be checked against the true one.
How a fraction becomes a decimal
A fraction is already a division: the line means "divided by". So converting one is simply carrying that division out.
- Numerator — the top number, e.g. 5
- Denominator — the bottom number, e.g. 8
- Decimal — the answer, e.g. 0.625
There is a shortcut when the denominator divides into a power of ten. Scale the fraction until the bottom is 10, 100 or 1,000, and the top is the answer: 2/5 = 4/10 = 0.4 and1/25 = 4/100 = 0.04. Long division is the general method for when it does not.
Long division also explains repeating decimals. Each step leaves a remainder, and there are only so many remainders a denominator can produce — dividing by 7 can only ever leave 1 through 6. Once a remainder comes back, the digits that followed it come back too, for ever. That is why 1/7 repeats after exactly six digits.
Common fractions as decimals
| Fraction | Decimal | Type |
|---|---|---|
| 1/4 | 0.25 | Terminating |
| 5/8 | 0.625 | Terminating |
| 1/25 | 0.04 | Terminating |
| 1/3 | 0.(3) | Repeating, 1 digit |
| 1/6 | 0.1(6) | Repeating, 1 digit |
| 1/7 | 0.(142857) | Repeating, 6 digits |
The split down the Type column is decided entirely by the denominator. Four, eight and twenty-five are built from 2s and 5s, so they terminate; three, six and seven are not, so they repeat.