Wire Gauge & Size Calculator

Wire Gauge Calculator Find the minimum safe wire size in seconds. Enter voltage (V), current (A), run length (ft/m), and allowable voltage drop (%) — the app returns the smallest conductor that satisfies both voltage drop and ampacity, and shows you which one set the size. New in this version • IEC (mm²) sizing — now alongside NEC (AWG/kcmil); switch standards in one tap • Ampacity check — sizes by current-carrying capacity, not just voltage drop • More accurate AC — power factor, conductor temperature, and reactance • Continuous load (125%), insulation rating, and installation-method options Features • Results in AWG/kcmil, inch, mm, and sq.mm at a glance • Conductor materials: Copper, Aluminum & Steel • Multiple parallel conductors per phase • DC, AC single-phase, and three-phase (3- & 4-wire) • Quick-pick common supply voltages + shareable results Perfect for • Low-voltage DC — automotive, RV, solar • Residential AC — single-phase 120 V / 230 V • Industrial three-phase — 480 V (US) / 400 V (EU) • Long-distance power runs Always verify results against your local electrical code.