Decimal to fraction calculator
Convert a decimal into a simplified fraction and mixed number when applicable.
What this calculator covers
Use this calculator to rewrite a decimal as a simplified fraction without hiding the reduction steps.
Terminating decimals convert exactly, while longer decimal inputs switch to a documented best rational approximation so the result stays readable.
Frequently asked questions
- When does the calculator switch from exact to approximate?
- Decimals with six or fewer decimal places are converted exactly by clearing the decimal point and reducing the resulting fraction. Inputs with more than six decimal places switch to a continued-fraction search that finds the closest fraction with a denominator up to one million.
- What is a mixed number and when does it appear?
- A mixed number combines a whole part and a proper fraction, such as 1 3/4 instead of 7/4. The calculator shows it automatically whenever the absolute value of the input is at least one.
- Can I convert negative decimals?
- Yes. The sign is carried through the conversion and appears on the numerator of the resulting fraction.
- How do I know if the result is exact or an approximation?
- The result panel shows the conversion mode alongside the absolute error. An exact conversion will show zero error; an approximation will show a small non-zero error value.
Tool
Run the calculation
Result
RESULT · FRACTION
â„–146
Primary result
5/4
1.25 converts to 5/4, which is 1 1/4 as a mixed number.
- Simplified fraction
- 5/4
- Mixed number
- 1 1/4
- Conversion mode
- Exact terminating-decimal conversion
- Absolute error
- 0
Step-by-step solution
- 1.Start from the decimal 1.25.
- 2.Because the decimal terminates quickly, the calculator converts it exactly by clearing the decimal places and reducing the resulting fraction.
- 3.Reduce the fraction to lowest terms as 5/4 and express it as 1 1/4 when the absolute value is at least 1.
Walkthrough
Visual walkthrough
Decimal-to-fraction conversion is either exact decimal clearing or a best-fit rational search when the decimal runs long.
01
Inspect the decimal form
1.25
Short terminating decimals can be converted exactly, while longer decimals may be more useful as a close rational approximation.
02
Build the numerator and denominator
5/4
The calculator either clears the decimal places directly or searches continued-fraction convergents until the tolerance is met.
03
Reduce and read the final form
The simplified fraction is the primary result, with a mixed-number view added whenever the magnitude is at least one whole.
5/4 = 1 1/4