AC Sizing & Cooling Load Calculator

Estimate the cooling capacity (BTU/h, tons and kW) a room needs from its floor area, ceiling height, occupancy, kitchen and sun exposure, using the standard room-sizing rule of thumb. Useful for picking a window, portable or split air-conditioner. The result is a planning estimate — real cooling load depends on insulation, glazing, climate, internal heat gain and air infiltration, so for whole-house or commercial sizing use a proper Manual J calculation. Pure arithmetic, in your browser.