BTUcalc

BTU Calculator for a 1200 sq ft Room

A 1200 sq ft room is 1200 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.

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Try: Room area=1200, Ceiling height=8, People usually in room=1, Room type=living, Sun exposure=avg, Insulation quality=avg, Climate zone (1–5)=3 → 24,000 BTU, 2.00 ton, 24,000 BTU (2 ton), 42,000 BTU

How to use

A 1200 sq ft room is 1200 square feet. At the common rule of 20 BTU per square foot, the base cooling load is about 24,000 BTU before people, sun and climate are added. A 1,200 sq ft house or apartment needs whole-home cooling. Plan near 2–2.5 tons (24,000–30,000 BTU), confirmed by a Manual J load calc. Use the calculator to fold in your real ceiling height, insulation and climate zone.

Reviewed by HVAC technician Mike R.

FAQ

What size AC for a 1200 sq ft room?

Start from about 24,000 BTU and adjust upward for sunny windows, poor insulation or a hot climate, and downward for a shaded, tight room. Most 1200 sq ft rooms land near a 5,000–12,000 BTU unit depending on those factors.

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