Count the places, not the digits before the point
The denominator is a power of ten determined by the number of digits after the decimal point. A three-place decimal starts over 1000; a one-place decimal starts over 10.
Remove the decimal point to form the numerator, retaining the sign. Leading zeros do not change the integer value, but their places still matter when choosing the denominator.
Reduce after constructing the fraction
Find a common divisor and cancel it from both parts. Trailing zeros are harmless: 0.50 starts as 50/100 and reduces to the same 1/2 as 0.5.
Whole numbers can be written with denominator one. Decimals greater than one naturally produce improper fractions; you do not have to convert them to mixed numbers.
A finite decimal is not a repeating decimal
The written value 0.333 is exactly 333/1000, not exactly 1/3. An ellipsis or repeating bar makes a different mathematical statement. This converter handles finite written decimals only.
Scientific notation changes the power of ten. The tool accepts bounded exponents and digit counts, which are listed beside it; use those limits rather than assuming arbitrary precision.
LET’S WORK IT THROUGH
Convert 0.875 to a fraction.
- There are three decimal places, so write 875/1000.
- The greatest common divisor is 125.
- 875 ÷ 125 = 7 and 1000 ÷ 125 = 8.
THE ANSWER0.875 = 7/8 exactly.
YOUR TURN
A small check for understanding.
Convert 1.25 to an improper fraction.
Reveal the answer
5/4. Start with 125/100 and divide both parts by 25.
Now try your own numbers.
The decimal to fraction includes input guidance and the limits of its supported calculations. Use it alongside the method above.
Open Decimal to fraction ↗A note on precision: preserve exact fractions where possible and round numerical results at the end. Found an unclear step? Prepare a correction report.