Electric Cable Size Calculator

While an electric cable size calculator is a powerful planning tool, it is not a substitute for a certified electrician.

By inputting these variables, the calculator cross-references official tables—such as the National Electrical Code (NEC) in the US or BS 7671 in the UK—to provide the safest AWG (American Wire Gauge) or mm² (metric) size for your specific job. To help you get the most accurate calculation, let me know: What is the of your devices? How long is the cable run from the power source? Will the cable be indoors, outdoors, or buried ? electric cable size calculator