BTU for Room Heating Calculator
Heating BTU/hr = ft² × insulation factor × ΔT.
Result
General calculation reads
Amazon affiliateAs an Amazon Associate we may earn from qualifying purchases. This does not add cost for you.
How to use this calculator
- Enter room area.
- Pick insulation level.
- Enter the design ΔT (typical: 50-70°F).
About this calculator
Heating load depends on three factors: room size, how well-insulated the room is, and how cold it gets outside. ΔT (delta temperature) is the design indoor temp minus the design outdoor low. Standard US design temps: 70°F inside, climate-zone-dependent low (-10°F to 30°F). For whole-home systems, use a Manual J calculation.
Frequently asked
What ΔT should I use?+
Old vs new construction?+
Does this match my furnace size?+
Heat-pump vs furnace?+
Why include insulation?+
Related calculators
More tools you might like
Hand-picked tools that pair well with this one — same audience, same intent.
BTU/hr needed = ft² × climate factor (20-30 BTU/ft² for typical US climates).
L × W × H = ft³. Used for air-change calculations and AC/heating sizing.
1 ton = 12,000 BTU/hr cooling. Convert sqft → tons (rule-of-thumb sizing) OR BTU → tons (direct).
Furnace BTU = ft² × climate-zone factor (30-60 BTU/ft²).
CFM (cubic feet per minute) = BTU/hr × 0.07. Used for sizing ducts.
A room-by-room home-staging checklist — declutter, depersonalize, repair, lighting, soft-staging touches, and a "day-of-showing" 30-minute reset.