Inch measurements are most commonly given as mixed numbers, with the whole number of inches listed first and then the remaining fraction after (for example, 4 1/3 inches). Many people want to know how to convert these mixed-number fractions into decimals. The process will only take you a matter of seconds once you know the formula and have a calculator nearby. In addition to inches, this formula can be applied to all measurements whenever you want to convert them from mixed-number form to decimal form.
Measure the length or height and write it down (for example, 8 3/8 inches).
Divide the top number of the fraction on the right-hand side of the mixed number by its denominator (the number underneath it). Using the example in Step 1, you would divide 3 by 8 and get 0.375.
Write the measurement as a decimal, starting with the whole number of inches first, followed by a decimal point and the number you computed in Step 2. For example, 8 3/8 inches would be converted to 8.375 inches.