AC Requirement Calculator

Cooling load estimator

AC Size Calculator

Enter your room's size and conditions to get the exact BTU/hr cooling load, the tonnage required, and the AC unit size(s) that will actually cool it — tuned for hot, humid climates.

Room details

Room area (sq ft)

Length (ft)

Width (ft)

Room type Bedroom Living / dining room Office / study Kitchen Server room / heavy electronics

Ceiling height Standard (up to 9 ft) High (9–12 ft) Very high (12 ft+)

Sun exposure Low / mostly shaded Moderate High (west-facing / direct sun)

Floor position Middle / ground floor Top floor (under exposed roof)

Top-floor rooms under a directly-exposed roof pick up extra heat and need roughly 10% more capacity.

Wall insulation Poor (old brick / tin, uninsulated) Average (standard plastered brick) Good (insulated / modern construction)

Poorly insulated walls let more outside heat in and need extra capacity; well-insulated walls need less.

Windows

Each window adds heat gain through the glass.

Exterior doors

Doors to outside or unconditioned space add infiltration load.

Regular occupants

Baseline assumes 2 people; each extra person adds heat load.

Heat-generating electronics

TVs, desktop PCs, ovens, etc.

Cooling requirement

0BTU/hr

Exact tonnage: 0.00 ton

Recommended AC size

–

How many units of a given size?

1.0 Ton 1.5 Ton 2.0 Ton 2.5 Ton 3.0 Ton 4.0 Ton 5.0 Ton

You'll need 1 unit(s) of this size to cover the load.

This load exceeds a single standard split unit. Consider two smaller units placed for even airflow, or a ducted/central system, rather than one oversized AC.

Estimate uses a 20 BTU/hr per sq ft base load, adjusted for ceiling height, sun exposure, roof exposure, wall insulation, room type, windows, doors, occupants and electronics.