Convert Ohm Circular Mils per Foot to Nanoohm Metres

Formula

nΩ·m = Ω·cmil/ft × 1.662426112525

Derivation from SI units:

• 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 nΩ·m = 10⁻⁹ Ω·m = 0.1 µΩ·cm
• 1 Ω·cmil/ft = 1.662426112525 × 10⁻⁹ Ω·m ÷ 1 × 10⁻⁹ Ω·m per nΩ·m = 1.662426112525 nΩ·m

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

Worked examples

1. A reading of 16.8 Ω·cmil/ft converts to 27.92875869 nΩ·m.
   16.8 Ω·cmil/ft × 1.662426113 = 27.92875869 nΩ·m
2. A value of 100 Ω·cmil/ft is 166.2426113 nΩ·m.
   100 Ω·cmil/ft × 1.662426113 = 166.2426113 nΩ·m

Where it's used

Ohm Circular Mils per Foot are used for US wire tables and AWG calculations, while nanoohm metres appear in physics and materials handbooks. Both measure electrical resistivity, so the conversion is a fixed factor.

Ohm Circular Mil per Foot to other electrical resistivity units

Frequently asked questions

Sources

• 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) .
• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .

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