Fraction to Decimal to MM Converter
Type any measurement — 3/8, 0.375, or 9.5 mm — and get all three forms back. Built for drill bits, screw diameters, and every dimension that arrives in the wrong unit.
Common fractions (16ths)
| Fraction | Decimal (in) | MM |
|---|
How It Works
One inch is exactly 25.4 mm, so decimals convert by multiplication — but fractions must round to the nearest 64th, the smallest graduation on most rules. The converter accepts fractions (3/8), mixed numbers (1 3/8), decimals (0.375), and millimeters (9.5 mm), then shows all three forms. Drill-bit and screw diameters in decimals map to the nearest fraction the same way machinists read them.
Printable PDF
Download the Fraction to Decimal to MM Converter and its formula sheet as a free PDF.
Free download. (Email capture can be wired to a form provider later — see README.)
Reference values only — always confirm critical fastening decisions against your engineering specification or the fastener manufacturer.