Performance is affected by your home's layout, insulation, and regional climate, but generally 5,000 Btus of fire power will heat 200 square feet. For a precise match for your space, have a dealer visit your home and recommend a model. Just keep in mind that the warmth from your stove will be concentrated in rooms closest to where it's installed. If used for supplemental heat, one trick is to put the stove near a furnace return vent and run the furnace fan to circulate warmed air throughout your home. A ceiling fan with its blades turning in reverse can also help distribute warmed air.
Tip: Hearing a stove in action on the dealer's floor is just as important as seeing one. If the whir of the fans or the hum of the auger motor bothers you, find another model.