Convert Ohm Circular Mils per Foot to Ohm Centimetres

Formula

Ω·cm = Ω·cmil/ft × 1.662426112525 × 10⁻⁷

or Ω·cm = Ω·cmil/ft ÷ 6015304.935757

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 Ω·cm = 0.01 Ω·m
• 1 Ω·cmil/ft = 1.662426112525 × 10⁻⁹ Ω·m ÷ 0.01 Ω·m per Ω·cm = 1.662426112525 × 10⁻⁷ Ω·cm

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

Worked examples

1. A reading of 16.8 Ω·cmil/ft converts to 0.000002792875869 Ω·cm.
   16.8 Ω·cmil/ft × 1.662426113 × 10⁻⁷ = 0.000002792875869 Ω·cm
2. A value of 100 Ω·cmil/ft is 0.00001662426113 Ω·cm.
   100 Ω·cmil/ft × 1.662426113 × 10⁻⁷ = 0.00001662426113 Ω·cm

Where it's used

Ohm Circular Mils per Foot are used for US wire tables and AWG calculations, while ohm centimetres appear in silicon wafer resistivity (for example 1–10 Ω·cm). 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.