BTU Calculator
Calculate the optimal BTU capacity needed for your room to ensure efficient cooling or heating with our easy-to-use calculator.
Room Specifications
Room Dimensions
120 sq ft
Environmental Factors
Medium
Low Medium High
Average
Poor Average Excellent
2
1 5 10
Moderate
Cool Moderate Hot
Room Type
Calculation Results
Recommended BTU Capacity 5,000 BTUs per hour
AC Unit Recommendations
Small Units
5,000 – 7,000 BTU
- Small rooms (100-300 sq ft)
- Window units
Medium Units
8,000 – 12,000 BTU
- Medium rooms (300-550 sq ft)
- Window or portable units
Large Units
13,000 – 18,000 BTU
- Large rooms (550-1,000 sq ft)
- Portable or split units
Extra Large
18,000+ BTU
- Very large spaces (1,000+ sq ft)
- Multi-split or central units
BTU Calculation Factors
About BTU Calculation
What is BTU?
BTU (British Thermal Unit) is a unit of heat defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. In HVAC, BTU measures the cooling or heating capacity of air conditioners and heaters.
Why is accurate calculation important?
An air conditioner with too few BTUs won’t cool your space effectively, while one with too many BTUs will cycle on and off too frequently, reducing efficiency and not properly dehumidifying the air.
Calculation Formula
Our calculator uses the following formula as a basis:
BTU = (Room Volume in cubic feet) × (Insulation Factor) ×
(Sunlight Factor) × (Occupancy Factor) × (Climate Factor) ×
(Room Type Factor)
(Sunlight Factor) × (Occupancy Factor) × (Climate Factor) ×
(Room Type Factor)
Each factor is adjusted based on your specific inputs to provide a personalized recommendation.