BTU Calculator

▼

Calculate British Thermal Units (BTU) needed for heating and air conditioning (AC) based on room size, ceiling height, insulation quality, sun exposure, and occupants.

Room & Climate Specifications

Length (ft):

Width (ft):

Ceiling Height (ft):

Presets:

Insulation Quality:

Sunlight Exposure:

Climate Zone:

Number of Occupants:

Number of Windows:

Is this a kitchen or has major heat appliances? (+4,000 BTU)

Cooling Capacity Needed

7,000 BTU/hr

AC Tonnage 0.58 Tons

Kilowatts (kW) 2.05 kW

Heating Capacity Needed 8,750 BTU

Room Area & Vol 300 sq ft (2,400 cu ft)

Commercial Unit Sizing Recommendation 8,000 BTU (Medium Room 250 - 350 sq ft) Air conditioners are sold in standard capacities. If your exact need is 7,000 BTU, purchasing a 8,000 BTU unit ensures efficient cooling without overburdening the compressor.

Estimated Operating Cost (15 SEER @ $0.16/kWh) ~$0.075 per hour of continuous runtime

~$18 per month (~8h/day)

Detailed BTU Factor Breakdown

Factor / Component	Value	BTU Impact
Base Room Area (20 BTU/sq ft)	300 sq ft	+6,000
Windows Thermal Gain	2 windows (+500 BTU/ea)	+1,000
Total Net Cooling Load:		7,000 BTU/hr

Understanding your calculation

Method, example and limitations

How the calculation works

BTU estimates approximate a heating or cooling load from the selected room and environmental assumptions. One BTU per hour is approximately 0.293 W of thermal power.

Example to check

A capacity of 12,000 BTU/h is approximately 3.52 kW of thermal output, rather than necessarily 3.52 kW of electrical consumption.

Before using the result

Insulation, climate, windows, occupancy and equipment efficiency affect sizing. A simple room estimate is not a professional load calculation.

Calculation methodology · Report a result that needs review