How To Calculate Cable Size In Sq Mm Formula May 2026

For a three-phase circuit:

The most reliable formula for cable sizing (especially for longer runs) uses voltage drop as the limiting factor. For a single-phase AC or DC circuit: how to calculate cable size in sq mm formula

[ A = \frac\sqrt3 \times \rho \times I \times LV_d ] For a three-phase circuit: The most reliable formula

[ A = \frac2 \times \rho \times I \times LV_d ] how to calculate cable size in sq mm formula