Wire Gauge Calculator — Cable Size for Your Electrical Load

Wire size depends on the current (amps) it must carry continuously, plus a safety margin, and the run length (longer runs need thicker wire to limit voltage drop). As a starting reference: 1.5mm² wire safely carries about 16A, 2.5mm² about 20-25A, 4mm² about 25-32A for typical household wiring — always follow your local electrical code (e.g., IS 732 in India) rather than relying solely on a calculator for final wiring decisions.

Voltage drop is the loss of voltage along a wire due to its resistance, which increases with wire length and current. Excessive voltage drop (commonly kept under 3-5% for branch circuits) causes dimming lights, reduced motor performance, and wasted energy as heat. Longer wire runs need a thicker gauge to keep voltage drop within acceptable limits.

mm² (square millimeters) is the metric standard used in India, Europe, and most of the world, directly describing the wire's cross-sectional area. AWG (American Wire Gauge) is used in the US — counterintuitively, a SMALLER AWG number means a THICKER wire (e.g., 10 AWG is thicker than 14 AWG). This tool supports both systems with conversion.