Convert Ohm Square Millimetres per Metre to Ω·cmil/ft

Formula

Ω·cmil/ft = Ω·mm²/m × 601.5304935757

Derivation from SI units:

• 1 Ω·mm²/m = 10⁻⁶ Ω·m (resistance in Ω of a 1 m wire with 1 mm² cross-section)
• 1 Ω·cmil/ft = (π/4 × (25.4 µm)²) ÷ 0.3048 m Ω ≈ 1.6624 × 10⁻⁹ Ω·m; a circular mil is the area of a 1-mil-diameter circle
• 1 Ω·mm²/m = 0.000001 Ω·m ÷ 1.662426112525 × 10⁻⁹ Ω·m per Ω·cmil/ft = 601.5304935757 Ω·cmil/ft

Both units are defined exactly, so the factor is exact. Ohm Square Millimetre per Metre definition: ohm square millimetre per metre; Ohm Circular Mil per Foot definition: ohm circular mil per foot.

Worked examples

1. A reading of 0.0282 Ω·mm²/m converts to 16.96315992 Ω·cmil/ft.
   0.0282 Ω·mm²/m × 601.5304936 = 16.96315992 Ω·cmil/ft
2. A value of 0.72 Ω·mm²/m is 433.1019554 Ω·cmil/ft.
   0.72 Ω·mm²/m × 601.5304936 = 433.1019554 Ω·cmil/ft

Where it's used

Ohm Square Millimetres per Metre are used for cable and wire resistance (R = ρ × length ÷ mm²), while ohm circular mils per foot appear in US wire tables and AWG calculations. Both measure electrical resistivity, so the conversion is a fixed factor.

Ohm Square Millimetre per Metre to other electrical resistivity units

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .
• Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "circular mil".
• Copper Wire Tables, NBS Handbook 100 (International Annealed Copper Standard), National Bureau of Standards (now NIST) .

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.