Decimal to Fraction Calculator
Turn a decimal into a reduced fraction — handy for homework and shop measurements. Click any i for detail.
Decimal
Decimal value
i
Decimal
The number you want as a fraction (can be negative). |
|
|---|---|
Rounding places
i
Places
How many decimal places to keep before converting (limits floating-point noise). |
How to use this calculator
- Enter the decimal (for example 0.375).
- Choose how many decimal places to honor before converting.
- Read the reduced fraction and optional mixed number.
- Check the decimal reconstruction if you need to verify rounding.
Results explained
Any terminating decimal can be written as an integer over a power of ten, then reduced by dividing numerator and denominator by their greatest common divisor. Repeating decimals need a different algebraic trick; this page focuses on rounded/terminating inputs, which covers most homework and measurement cases.
Quick reference: decimal → fraction
Scale by 10^places, then divide by GCD.
| Item | Detail |
|---|---|
| 0.5 | 1/2 |
| 0.375 | 3/8 |
| 1.25 | 5/4 or 1 1/4 |
| 0.3333 (4 places) | 3333/10000 |
Repeating expansions like 1/3 ≈ 0.333… are approximate once you fix a place count.
How the estimate is built
fraction = round(decimal × 10^p) / 10^p, then reduce by gcd(numerator, denominator).
Example scenario
0.375 with 4 places → 3750/10000 → reduce → 3/8.
FAQ
Why does 0.1 look weird in some tools?
Binary floating point cannot store 0.1 exactly. Choosing a place count (and rounding) makes the fraction match what you typed on paper.
Can I get mixed numbers?
Yes — when the absolute value is greater than 1, the page also shows a mixed form such as 1 1/4.
What about repeating decimals?
Enter enough repeating digits and a high place count for an approximation, or convert with the algebraic repeating-decimal method in class.
Does negative work?
Yes. The sign sticks to the numerator after reduction.