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BTU to Tons

3.5 Ton to BTU Converter

3.5 refrigeration tons equal 42,000 BTU per hour. Multiply 3.5 by 12,000.

Enter the size in tons, like 1.5.

refrigeration tons
Cooling capacity

3.5 refrigeration tons equal 42,000 BTU per hour.

42,000BTU/hr

Sold as a 3.5 ton AC. Exact: 3.5 tons.

1 ton = the cooling of melting 2,000 lb of ice per day.
Cooling kW
12.309

1 refrigeration ton = 12,000 BTU/hr. Cooling kW is cooling capacity, not electricity use.

  • Tons = BTU/hr ÷ 12,000
  • Cooling kW = BTU/hr × 0.2930710702 ÷ 1,000
Your numbers3.5 × 12,000 = 42,000
Decimal places

Common AC ratings

Choose a capacity to fill the calculator, or open its worked example.

Worked examples:6,0009,00012,00018,00024,00036,000

How the conversion works

Multiply 3.5 by 12,000 to calculate the capacity.

3.5 × 12,000 = 42,000 BTU/hr

Cooling capacity: 12.309 cooling kW. Cooling kW is not the electricity the AC uses.

Compare 3.5 with 3 and 4 tons

Compare 3.5 with 3 and 4 tons
TonsBTU/hrCooling kWSize class
336,00010.55063 ton
3.542,00012.3093.5 ton
448,00014.06744 ton

Does 3.5 tons mean it fits my space?

A refrigeration ton is a capacity unit, equal to 12,000 BTU/hr; it is not the unit's weight.

There is no universal area-to-tonnage ratio. Room conditions, building design and climate affect the required capacity.

Whole-home systems require a separate load calculation.