Wire Parameter Calculator

This Javascript web calculator will calculate the resistance and ampacity for the wire gauge you enter below. Note: Ampacity is based on a curve fit to MIL-STD-975. Ampacity is the rms current which a device can carry within specified temperature limitations in a specified environment dependent upon: a) temperature rating, b) power loss, c) heat dissipation. The ampacity for a cable is thus based on physical and electrical properties of the material, the construction of the conductor, the insulation composition, ambient temperature, and environmental conditions adjacent to the cable. Having a large overall surface area may dissipate heat well if the environment can absorb the heat.