BTU Calculator
Estimate the heating or cooling BTUs a room needs from its floor area.
BTUs required6,000BTU
In kilowatts1.76kW
Area in m²27.9m²
A common rule of thumb is about 20 BTU per square foot of floor area. BTUs required = floor area (sqft) × 20. A 300 sqft room needs ≈ 300 × 20 = 6,000 BTU (≈ 1.76 kW). Raise the BTU-per-sqft figure for sunny rooms, high ceilings, poor insulation or kitchens, and lower it for shaded, well-insulated spaces.
Questions
How many BTUs do I need to cool a room?
A starting point is about 20 BTU per square foot. A 300 sqft room needs roughly 6,000 BTU, though sun, ceiling height and insulation shift the figure.
How do BTUs relate to kilowatts?
One BTU per hour is about 0.000293 kW, so 6,000 BTU is roughly 1.76 kW. Air-con and heat pumps are often rated in both units.