Convert in to mm
Use the live converter below to translate between Inch (in) and Millimeter (mm). Scroll further for quick examples, formula tips, and related units.
Convert
in → mm
Formula
1 in = 25.4 mm
Conversion sourcesTap or click to view references
The International System of Units (SI) — NIST Special Publication 330
National Institute of Standards and Technology (NIST). The SI Brochure (SP 330) is the definitive English edition of the BIPM SI tables. NIST’s edition lists the official constants and conversion factors tying inch-pound units to SI, which SwapUnits applies for length, mass, temperature, pressure, volume, and related conversions. See /standards/nist-si-tenfold for the complete decimal multiple/submultiple table. View source · View SI table
Results update as you type. Swap the direction to convert back from mm to in.
in to mm quick table
Multiply any row by the same factor to scale results. Use the converter above to enter exact values with your own units.
| Inch (in) | Millimeter (mm) |
|---|---|
| 0.25 in | 6.35 mm |
| 0.5 in | 12.7 mm |
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 25 in | 635 mm |
| 100 in | 2,540 mm |
mm back to in
Keep the reciprocal handy when double-checking calculations or undoing a conversion.
| Millimeter (mm) | Inch (in) |
|---|---|
| 0.25 mm | 0.0098 in |
| 0.5 mm | 0.0197 in |
| 1 mm | 0.0394 in |
| 2 mm | 0.0787 in |
| 5 mm | 0.1969 in |
| 10 mm | 0.3937 in |
| 25 mm | 0.9843 in |
| 100 mm | 3.937 in |
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