Keep a 16-gauge extension cord under 50 feet for a 10-amp tool.

50 feet max, and even that is pushing it if you want the tool to run properly.

The issue isn’t just safety—though that’s part of it. At 10 amps, a 16-gauge cord longer than 50 feet will have enough voltage drop to make your tool run sluggish, overheat the cord, and potentially trip breakers. The math says at 100 feet you’re losing almost 20 volts on a 120V circuit. That’s enough to kill performance and generate waste heat in the wire.

If you can, go with a 14-gauge cord for anything over 25 feet at 10 amps. 16 gauge is fine for light-duty stuff (lamps, small fans, battery chargers) but for a real 10-amp tool like a circular saw or shop vac, you want the thicker wire.

Don’t let a long skinny cord be the reason your tool craps out mid-cut. Get the right gauge.