5 Things to Know About Extension Cords for High-Amperage Tools

Use a 12-gauge or thicker cord under 100 feet for any tool pulling 15 amps, like a pressure washer. Thinner cords cause voltage drop, making tools struggle, overheat, or trip breakers.

Match cord gauge to your tool’s amp rating. For a standard 15-amp tool, a 12-gauge cord is safe up to 100 feet. For longer runs over 100 feet, step up to 10-gauge.

Check the AWG number on the cord jacket—lower numbers mean thicker wire. Never guess; the gauge is printed on the cord.

Avoid light-duty or indoor cords. Only use cords marked “W” or “WA” for outdoor use—they have heavier insulation that resists cracking in sun or cold.

Don’t risk burning out your tool or starting a fire to save twenty bucks. A proper cord is cheap insurance.