Toolstia / Decimal to fraction calculator

Decimal to fraction calculator

Enter a decimal such as 0.375 to get the exact fraction 3/8. Repeating decimals work too: write the repeating part in brackets, as in 0.(3) or 0.1(6). For a long measured decimal like 3.14159 the tool also offers the closest simple fraction.

Enter a decimal number. Put repeating digits in brackets, like 0.1(6).

A decimal you type is converted exactly: 0.375 is 375/1000, which reduces to 3/8. If the number came from a measurement, like 3.14159, the closest simple fraction (355/113) may be more useful.

How it works

  1. Enter the decimal number.
  2. Read the exact fraction and the mixed number.
  3. Check the closest simple fraction if one is shown.

Terminating decimals

A decimal with n digits after the point is that number over 10 to the power n, then reduced. 0.375 = 375/1000 = 3/8.

Repeating decimals

Put the repeating digits in brackets. 0.(3) is 1/3, 0.1(6) is 1/6 and 0.(142857) is 1/7. The tool uses the standard method of subtracting shifted copies to cancel the repeat.

Closest simple fraction

A typed value like 3.14159 is exactly 314159/100000, but 355/113 is much simpler and very close. The tool finds the best fraction up to a denominator you choose, using continued fractions.

Whole parts

Numbers above 1 are also shown as mixed numbers, such as 2.5 = 5/2 = 2 1/2.

Questions

Is 0.333 the same as 1/3?

No. 0.333 is 333/1000. Use 0.(3) for the repeating decimal 1/3.

Does it handle negatives?

Yes, with a leading minus sign.

Is anything uploaded?

No. Your number stays in your browser and is never sent anywhere.