A typical extension cord wire is a 16-gauge, meant for everyday chargers and lamps of up to 15-amp, but a heater needs that full capacity on its own— and oftentimes more.

Wire is basically measured in a gauge number. A typical 16-gauge wire would have a diameter of roughly 0.051-inch, not counting for the insulation, all of it consisting of stranded wire.

I figure if I wire up the rear speakers, I should do it the right way once and not do it again. I've already pulled a number of other cables to a similar spot, so I'm not to worried about the pull ...

If I use the calculator that AnalogChipHead provided, 200 feet of 16-gauge wire has a resistance of 0.803 ohms. Does this mean I'm more or less in the clear?

Its 16 gauge wire is perfect for attaching to brake lights, turn signals, and tail lights. This versatile product makes a perfect switch for your old wiring harness.

Measurements are based on the American Wire Gauge (AWG) standard, and you can find 12-, 14-, 16-, and 18-gauge speaker wire, 12 being the thickest. Generally, thicker wires reduce resistance but ...