Convert a real number into a fraction. How to use the decimal to fraction calculator. This calculator allows you to convert real numbers, including repeating decimals, into fractions. Enter a decimal number in the space above, then press Convert to Fraction to send the number and calculate the equivalent fraction. Number formats You may enter simple rational numbers with the whole portion separated from the decimal portion by a decimal point (ex. 12.25). You may also convert to fractions numbers with infinitely repeating digits by enclosing the repeating digits in parenthesis or by adding '...' at the end of the number.