AC Tonnage Calculator
1 ton = 12,000 BTU/hr cooling. Quick estimate: ft²/600 → tons.
Result
AC tons
3.00 (round to 3)
36,000 BTU/hr.
- Area1800 ft²
- ft² per ton600
- Raw tons3.000
- Round to ½3
- BTU/hr (rounded)36,000
Step-by-step
- Tons = 1800 / 600 = 3.00.
- Round up to nearest ½-ton increment: 3.
How to use this calculator
- Enter total floor area to cool.
- Adjust ft²/ton if you know your local norm (cooler climates: 700+; hotter: 500).
About this calculator
AC capacity is measured in tons (1 ton = 12,000 BTU/hr cooling, named after melting that much ice in 24h). Sizing rule of thumb: 1 ton per 500-650 ft² for typical US homes. For precise sizing in extreme climates or homes with unusual loads, a Manual J calculation is required.
Frequently asked
AC equipment comes in 0.5-ton increments. A 2.7-ton calculation usually rounds to a 3-ton unit.
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