8 Best Space Heaters (2026): Tested, Measured, and Mistreated

Why Large Space Heaters Aren’t More Powerful Than Small Heaters

Nope! It may seem counterintuitive, but large space heaters don’t necessarily heat any better than small ones.

Whatever their physical size, most space heaters in the US and Canada deliver about the same amount of heat. Space heaters top out at 1,500 watts, which is the highest safe operating load for a 15-amp household circuit. And aside from some low-power personal heaters here and there, most space heaters you’ll find on the market are 1,500-watt heaters.

What’s more, electric space heaters are all pretty much 100 percent efficient in converting that electricity to heat. Whether directly or indirectly, nearly all of that energy will eventually become heat.