AC Tonnage Calculator

Size an air conditioner from your home's area, ceiling height, and climate.

Floor area (sq ft)

Ceiling height (ft)

Climate factor (BTU per sq ft)

People (above 2, add 600 BTU each)

Recommended size (tons)

Last updated: 2026-08-30

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FAQ

What does AC tonnage mean?

One ton of cooling removes 12,000 BTU per hour — the heat absorbed by one ton of ice melting over a day.

Is bigger better?

Oversized units short-cycle: they cool fast but leave the air humid and wear out sooner, so proper sizing wins.

How accurate is this estimate?

It approximates a room-by-room load; a real Manual J calculation by an HVAC pro accounts for windows, insulation, and sun exposure.

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