How Do I Estimate the Appropriate BTU Capacity for Room Size?

The size of the room plays a critical role in determining your BTU requirement for effective heating or cooling. Larger spaces generally demand more BTUs to achieve and sustain the desired temperature, while smaller rooms require fewer BTUs. Estimating the suitable BTU capacity for your space involves using a British Thermal Unit calculator or following a simple rule of thumb. For rooms under 150 square feet, allocate 5,000 BTUs per hour per square foot. For rooms between 150 and 350 square feet, allocate 5,000 BTUs plus an additional 1,000 BTUs for every 100 square feet over 150. Rooms over 350 square feet should be divided, and the BTUs for each section calculated separately, then combined. Learn more about estimating BTU capacity for room size.