Decimal to Fraction Calculator
By Miikka · CalcBrew · Updated
Repeating decimals work too: type 0.33... (trailing dots) or 0.1(6) — digits in parentheses repeat.
Fraction
3/8
Improper fraction
3/8
The work
- 0.375 = 375/1,000 (3 decimal places → denominator 1,000)
- GCD(375, 1,000) = 125
- 375 ÷ 125 = 3 and 1,000 ÷ 125 = 8 → 3/8
Fraction to decimal
Exact decimal
0.41(6)
Rounded
0.416667
The digits in parentheses repeat forever: 0.41666…
How the conversion works
A terminating decimal converts in two moves. Write the decimal digits over a power of ten, then simplify with the greatest common divisor: 0.75 = 75/100, and since GCD(75, 100) = 25, dividing both gives 3/4.
Repeating decimals need the nines method. For 0.1(6) — that is, 0.1666... — subtract the non-repeating digits from all the digits: 16 − 1 = 15. The denominator gets one 9 for each repeating digit and one 0 for each non-repeating digit: 90. So 0.1666... = 15/90 = 1/6 exactly. Whether a fraction terminates or repeats is decided entirely by its denominator: only prime factors 2 and 5 give a terminating decimal (the 2ᵃ·5ᵇ rule).
Common decimal–fraction conversions
| Decimal | Fraction |
|---|---|
| 0.1 | 1/10 |
| 0.125 | 1/8 |
| 0.2 | 1/5 |
| 0.25 | 1/4 |
| 0.333... | 1/3 |
| 0.375 | 3/8 |
| 0.4 | 2/5 |
| 0.5 | 1/2 |
| 0.6 | 3/5 |
| 0.625 | 5/8 |
| 0.666... | 2/3 |
| 0.75 | 3/4 |
| 0.8 | 4/5 |
| 0.875 | 7/8 |
Frequently asked questions
Cite this calculator
CalcBrew. (2026). Decimal to Fraction Calculator. https://calcbrew.com/decimal-to-fraction“Decimal to Fraction Calculator.” CalcBrew, 2026, calcbrew.com/decimal-to-fraction.Link to https://calcbrew.com/decimal-to-fraction. Results are estimates; cite the underlying formula or data source for academic work.
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