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Both calculators run independently — change the inputs on either side to compare results.

HVAC BTU Room Sizing Calculator

Size an air conditioner or mini-split to a room. Enter the room length and width, the ceiling height, choose the room's sun exposure, and add the number of regular occupants to estimate the cooling capacity in BTU per hour you need.

Room Length (ft)

Room Width (ft)

Ceiling Height (ft)

Sun Exposure

Regular Occupants (people)

Construction

HVAC BTU Calculator

Estimates the BTU per hour needed to heat or cool a room based on its size, ceiling height, and insulation quality. Use it to size an air conditioner, heat pump, or furnace before purchasing.

Room Area (sq ft)

Ceiling Height (feet)

Insulation Quality

Key differences

	HVAC BTU Room Sizing Calculator	HVAC BTU Calculator
Category	Construction	Construction
Inputs required	5	3
Result	Cooling Capacity Needed (BTU/hr)	BTU Required (BTU/hr)
What it does	Size an air conditioner or mini-split to a room. Enter the room length and width, the ceiling height, choose the room's sun exposure, and add the number of regular occupants to estimate the cooling capacity in BTU per hour you need.	Estimates the BTU per hour needed to heat or cool a room based on its size, ceiling height, and insulation quality. Use it to size an air conditioner, heat pump, or furnace before purchasing.