Heating Load Calculator
Calculate heating BTU requirements for winter based on square footage, insulation, windows, exterior walls, and climate zone.
Total floor area of the space being heated
Standard ceilings are 8 ft. Vaulted or commercial spaces are often 10-12 ft.
How well-insulated is the building? Older homes with no wall insulation = poor.
Difference between desired indoor temp and your area's winter design temp — e.g. 70°F indoor - 0°F outdoor = 70°F
Count all windows in the space. Each adds ~1,200 BTU of heat loss.
Walls exposed to outdoor air — interior walls don't count
Your region's general climate. Cold zones have significantly higher heating demands.
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