Choose the right wire gauge for your electrical project.
Lower AWG number = thicker wire = more current capacity.
AWG 12 is standard for household 20A circuits.
Reach for this calculator when a quick, verified engineering computation is needed without opening specialised software. The formula used follows the relevant standard and is documented for reference.
Many engineering errors stem from applying a formula outside its valid range. Most standard engineering formulas have boundary conditions — material limits, temperature ranges, or loading assumptions — that must be satisfied for the result to be reliable.
An engineer compares two design options with different material grades. Running both through the relevant strength or stiffness calculation reveals which option meets the performance specification with an adequate safety factor, informing the material selection decision.
AWG 12 (20A) or AWG 10 (30A) for safety margin.