Calculators / Heating and cooling
BTU to tons
Put in BTU, tons or kilowatts. You'll get the other two, and the mini-split size that covers it.
Updated · How we check our numbers
Converted
24,000 BTU = 2 tons
That's 7 kW, and it's a standard size: a 24,000 BTU mini-split.
- BTU per hour
- 24,000
- Tons
- 2
- Kilowatts
- 7
Estimate for planning only, not professional advice. Check the manufacturer’s instructions, your local code and a licensed professional before you buy, build or install. Use at your own risk. Terms.
24,000 BTU/hr
tons = 24,000 ÷ 12,000 = 2
kW = 24,000 ÷ 3,412.14 = 7.03
Mini-split sizes
single-zone- 9,000 BTU0.75 tons, 2.6 kW, up to about 400 sq ftToo small
- 12,000 BTU1 ton, 3.5 kW, up to about 550 sq ftToo small
- 18,000 BTU1.5 tons, 5.3 kW, up to about 1,000 sq ftToo small
- 24,000 BTU2 tons, 7 kW, up to about 1,500 sq ftYour size
- 30,000 BTU2.5 tons, 8.8 kW, up to about 2,000 sq ftBigger
- 36,000 BTU3 tons, 10.6 kW, up to about 2,500 sq ftBigger
Square feet off the ENERGY STAR chart: 8 ft ceiling, average sun. A garage usually sizes up one step.
A ton of cooling is 12,000 BTU an hour: the heat it takes to melt a ton of ice in a day. It has nothing to do with the unit's weight.
Tons and BTU only convert. To find what a space needs, use its size, ceiling, insulation and climate in the mini-split calculator.
How we work it out
A ton of cooling is 12,000 BTU an hour. That's fixed by definition: it's the heat it takes to melt a ton of ice in a day.
tons = BTU per hour ÷ 12,000
kW = BTU per hour ÷ 3,412.14
The kW factor comes from NIST's conversion tables, which put a ton of refrigeration at 3,516.853 W. Mini-splits come in 9,000, 12,000, 18,000, 24,000, 30,000 and 36,000 BTU, so we round up to the next one. The square feet beside each size are off the ENERGY STAR sizing chart.
Where the numbers come from
Guides
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