Square Millimeter (mm²)
The square millimetre (mm²) is the area of a square with 1 mm sides, 10⁻⁶ m².
Symbol: mm² (ASCII: mm2)
Quantity: area
SI relation: 1 mm² = 0.000001 m² (exact)
Derivation: 1 mm² = (0.001 m)² = 10⁻⁶ m²
Exact: yes, by definition
Typical uses
- Electrical cable cross-sections (IEC 60228: 1.5, 2.5, 4, 6 mm² …)
- Stress calculations in N/mm² (= MPa)
- Orifice and nozzle areas
Convert square millimeters to other units
| Conversion | 1 mm² equals | Reverse |
|---|---|---|
| square millimeter to square meter | 0.000001 m² | square meter to square millimeter |
| square millimeter to square centimeter | 0.01 cm² | square centimeter to square millimeter |
| square millimeter to square foot | 0.00001076391042 ft² | square foot to square millimeter |
| square millimeter to square inch | 0.0015500031 in² | square inch to square millimeter |
Open the Area 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 2 with SI prefix milli.
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). Square Millimeter (mm²). Retrieved October 17, 2026, from https://scientificconverters.com/units/square-millimeter/
IEEE
Scientific Converters, "Square Millimeter (mm²)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/square-millimeter/