How this tool works
The fractional part is multiplied by your selected denominator and rounded to the nearest numerator. The result is reduced to its simplest form and carries into the whole number when necessary.
Home / Decimal and fractional inches
Decimal to Fractional Inches
Choose the precision that matches your ruler, tape measure or workshop requirement. The calculator simplifies the fraction and shows the rounding difference in millimetres.
Fractional inches—
Millimetres—
Rounding difference—
When it is useful
Useful for woodworking, machining, fabrication, DIY, imperial drawings and converting decimal call-outs into measurements that can be marked with an ordinary tape.
Accuracy and unit standards
Rounding to a coarser denominator deliberately changes the value. Always choose a tolerance appropriate to the task; safety-critical manufacturing requires calibrated equipment and specified tolerances.