BTU Calculator
Estimate cooling and heating BTU requirements based on room size and conditions.
BTU Estimate
Results are estimates. Consult an HVAC professional for precise sizing.
What is the BTU Calculator?
The BTU Calculator estimates the British Thermal Units required to cool or heat a room based on its dimensions, insulation quality, sun exposure, and local climate. BTU is a standard unit of energy used in heating and cooling systems.
How to Use
- Enter the room length, width, and ceiling height in feet.
- Select the insulation quality, sun exposure level, and climate zone.
- Click Calculate BTU to see cooling and heating estimates.
Frequently Asked Questions
What does BTU stand for?
BTU stands for British Thermal Unit. One BTU is the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit.
How accurate is this calculator?
This calculator provides a rough estimate using rule-of-thumb formulas. For accurate HVAC sizing, a professional Manual J load calculation is recommended.
Does ceiling height matter?
Yes. Higher ceilings mean more air volume to condition, which increases the required BTU capacity.
What is a BTU-to-kW conversion?
One kilowatt (kW) is approximately 3,412 BTU per hour. The calculator divides BTU by this factor to estimate electrical power draw.