Cooling Load Calculator

Estimate BTU cooling needed for a room

Room Length (ft)

Room Width (ft)

Ceiling Height (ft)

Sun Exposure

Number of Occupants

Quick whole-house cooling estimate

Total Conditioned Area (sq ft)

Insulation Quality

Design Temp Difference (F)

Formula

BTU = Area x Factor x Sun Multiplier + Occupant Load | 1 Ton = 12,000 BTU/hr

How many BTU do I need per square foot?

A general rule is 20-30 BTU per square foot for cooling. Poorly insulated homes may need 35+ BTU/sq ft.

What size AC do I need?

Multiply room area by 25 BTU/sq ft as a starting point. Adjust for sun exposure, ceiling height, and occupants.

What is a ton of cooling?

One ton of cooling equals 12,000 BTU/hr. A typical residential AC system is 1.5-5 tons.

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