5 Ways to Tell 14-Gauge From 16-Gauge Extension Cords

Cut the cord to check the wire diameter The only reliable method is cutting a small section and reading the wire gauge printed on the insulation. Unmarked cords are a guessing game.

Thickness is not a reliable visual clue A 14-gauge cord is slightly thicker and stiffer than 16-gauge, but different insulation thicknesses can make a 16-gauge cord look identical to a 14-gauge.

Weight is also unreliable Rubber versus vinyl insulation changes the weight, so a heavier cord does not guarantee a thicker gauge.

Never guess for high-power devices For space heaters, window ACs, or anything drawing 10–15 amps, the difference between 14 and 16 gauge is the difference between safe operation and a melting cord.

Buy a new cord with clear markings if unsure A new, clearly marked cord costs about ten dollars. Guessing is not worth the fire risk.