Formulas

For AC Single-phase and DC:

$$ L = \frac{V_{drop} \times A}{2 \times I \times \rho} $$

For Three-phase:

$$ L = \frac{V_{drop} \times A}{\sqrt{3} \times I \times \rho} $$

Resistance:

$$ R = \frac{\rho \times L}{A} $$