# Wire DC resistance calculator

This calculator calculates the DC resistance of a wire.

 Resistivity (µΩm) Conductivity (MS/m) Diameter (mm) Radius (mm) CSA (mm^2) Length (m) Multiplier Diameter (mm) Radius (mm) CSA (mm^2) Resistance (Ω)

The multiplier field can be used to factor in return path (multiplier=2), or Rrf/Rdc resistance factor from Skin depth calculator.

# Resistivity and permeability

Resistivity of a material is the resistance from face to opposite face of a 1m cube of a material. Resistivity varies with different metals, a few common conductors are listed below.

Permeability is the ratio of flux density to magnetising force, self inductance is proportional to permeability.

 Conductor Resistivity (µΩ-m) Relative Permeability (µr) Conductivity (MS/m) Copper 0.0168 59.52 1 Silver 0.0159 62.89 1 Aluminium 0.0282 35.46 1 Aluminium 7xxx annealed 0.045 22.22 1 ZA ZAL 0.059 17 1 Zinc 0.059 16.95 1 Brass 0.064 15.63 1 Nickel 0.064 15.63 1240 Iron 0.100 10.00 200 Tin 0.109 9.17 1 Solder (63/37 Eutectic) 0.145 6.90 1 Mild steel 0.20 5.00 800 Lead 0.22 4.55 1 Stainless steel 316 0.75 1.33 1 Stainless steel 17-7 PH 0.82 1.22 120

A note about stainless steels. Pure austenitic steels do not exhibit ferro magnetism, relative permeability is unity. Many stainless steels are austenitic, but the process of hardening them, or the hardening as a result of working them (eg drawing wire) can create martensite, and they may exhbit µr significant greater than unity. Be suspicious of hardened stainless steel, check it with a magnet. If it is attracted to the magnet, it may have high µr and as a result may have quite high RF resistance. Stainless 316 tends to not develop ferromagnetism with work, 304 a little, and in the table above, 17-7PH has quite high µr in the hardened state (you wouldn't use it in the annealed state).

# Examples

## Example 1

Other VK1OD tools.