Fraction to Decimal Calculator

3/4 as a decimal is 0.75, found by dividing 3 by 4. In millimeters that is 19.05 mm (0.75 × 25.4).

Multiply the inch value by 25.4. For example 1.5 inches is 1.5 × 25.4 = 38.1 mm. To go from millimeters back to inches, divide by 25.4.

Multiply the decimal by the denominator you want (16, 32, or 64), round to the nearest whole number, and place it over that denominator, then reduce. For example 0.3 inch at 1/16 precision is 0.3 × 16 = 4.8, rounded to 5, giving 5/16.

Tape measures and shop drawings use fractions, while CNC machines, 2020 Flex, and spreadsheets use decimals. Converting cleanly between the two avoids stacking rounding errors across a run of parts.

Divide the numerator by the denominator. For example, 3/4 means 3 divided by 4, which equals 0.75. The calculator does this instantly, but the long-division method works the same way by hand. For shop work, type any fractional measurement and read the decimal result, which is handy when your tools or CNC settings expect decimal inches.

Keep the whole number, then convert the fractional part by dividing its numerator by its denominator, and add the two together. For example, 2 1/2 becomes 2 plus 0.5, which equals 2.5. This calculator accepts mixed fractions directly, so you can enter a measurement like 5 3/8 and get 5.375 without doing the math yourself.

3/8 equals 0.375, found by dividing 3 by 8. This is one of the most common conversions in cabinet and woodworking layouts, since 3/8 inch shows up often in reveals, spacing, and panel thicknesses. Enter it in the calculator to confirm, or build out a full chart of the fractions you use most for quick reference at the bench.

You convert each fraction the same way regardless of its denominator: divide the top number by the bottom number. There is no need to find a common denominator first when you only want the decimal value. Enter each fraction separately, such as 1/16 and 7/32, and the calculator returns each decimal so you can compare or add the results.