Conversion Formula
$$L_{\text{mm}} = L_{\text{in}} \times 25.4$$
Multiply inches by 25.4 to get millimeters (exact conversion).
in to mm Conversion Table
| Inch (in) | Millimeter (mm) |
|---|---|
| 0.1 | 2.54 |
| 0.5 | 12.7 |
| 1 | 25.4 |
| 2 | 50.8 |
| 5 | 127 |
| 10 | 254 |
| 25 | 635 |
| 50 | 1,270 |
| 100 | 2,540 |
| 250 | 6,350 |
| 500 | 12,700 |
| 1,000 | 25,400 |
in to mm in Engineering
Length conversions are the most fundamental engineering conversions. Civil engineers work with feet and miles in the US or meters and kilometers internationally. Surveying uses chains, rods, and furlongs, while precision engineering requires mils and micrometers.
Inch: Primary US customary unit for detailed dimensions. Exactly 25.4 mm. Standard for pipe sizes, bolt sizes, and drawings.
Millimeter: Standard precision unit in metric engineering drawings, structural steel, and manufacturing.