Millimeter (mm)
The millimetre (mm) is one thousandth of a metre. It is the standard unit on engineering drawings in metric countries.
Symbol: mm
Quantity: length and distance
SI relation: 1 mm = 0.001 m (exact)
Derivation: 1 mm = 10⁻³ m
Exact: yes, by definition
Typical uses
- Engineering drawings and machining tolerances
- Fasteners, pipe and sheet thickness
- Rainfall (mm per hour or day)
Convert millimeters to other units
| Conversion | 1 mm equals | Reverse |
|---|---|---|
| millimeter to meter | 0.001 m | meter to millimeter |
| millimeter to kilometer | 0.000001 km | kilometer to millimeter |
| millimeter to centimeter | 0.1 cm | centimeter to millimeter |
| millimeter to mile | 6.213711922 × 10⁻⁷ mi | mile to millimeter |
| millimeter to foot | 0.003280839895 ft | foot to millimeter |
| millimeter to inch | 0.03937007874 in | inch to millimeter |
| millimeter to micrometer | 1000 µm | micrometer to millimeter |
| millimeter to nanometer | 1000000 nm | nanometer to millimeter |
| millimeter to yard | 0.001093613298 yd | yard to millimeter |
| millimeter to nautical mile | 5.399568035 × 10⁻⁷ nmi | nautical mile to millimeter |
| millimeter to angstrom | 10000000 Å | angstrom to millimeter |
| millimeter to mil | 39.37007874 mil | mil to millimeter |
Open the Length Converter to convert any value between all units.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Millimeter (mm). Retrieved October 17, 2026, from https://scientificconverters.com/units/millimeter/
IEEE
Scientific Converters, "Millimeter (mm)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/millimeter/