BTU to tons, kW and MBH
Type a number in any box and the rest convert instantly, with a table of common residential and light commercial system sizes.
1 ton = 12,000 BTU/h = 3.517 kW. 1 kW = 3,412.142 BTU/h. These are rates of heat flow (capacity), not the electricity a unit draws.
| Tons | BTU/h | kW |
|---|
One ton of cooling equals 12,000 BTU per hour, so divide BTU/h by 12,000 to get tons: 36,000 BTU/h is 3 tons and 24,000 BTU/h is 2 tons. In metric, 1 ton equals 3.517 kW, and 1 kW equals 3,412 BTU/h. A ton describes cooling capacity, not weight or the electricity the unit uses.
How to use the BTU to tons converter
Pick a unit
BTU per hour, tons, kilowatts or MBH (thousand BTU per hour).
Type the value
The other three convert as you type.
Check the size table
Common sizes from 1 to 25 tons with BTU/h and kW; your size is highlighted.
What the BTU to tons converter does
Four units
BTU/h, tons of refrigeration, kW and MBH, converted both ways.
NIST factors
1 BTU/h = 0.2930711 W and 1 ton = 3,516.853 W, from NIST SP 811.
Size table
Half-ton steps for residential systems, then common light commercial sizes.
Instant
Converts as you type, on any device.
- 1 ton of refrigeration
- 12,000 BTU/h = 3.516853 kW
- 1 kW
- 3,412.142 BTU/h
- 1 MBH
- 1,000 BTU/h
- Cost and privacy
- Free, no sign-up; runs in your browser
BTU to Tons Converter FAQ
How many BTUs are in a ton?
A ton of refrigeration is 12,000 BTU per hour. The name comes from the heat absorbed by melting one ton of ice over 24 hours.
How do I convert BTU to tons?
Divide BTU per hour by 12,000. For example, 48,000 BTU/h รท 12,000 = 4 tons, and 30,000 BTU/h is 2.5 tons.
How many kW is a ton of cooling?
About 3.517 kW of cooling capacity. That's heat removed, not electrical power: a 3-ton unit removes about 10.55 kW of heat while drawing far less electricity, depending on its efficiency.
What does MBH mean?
Thousands of BTU per hour, from the Roman numeral M for a thousand. 60 MBH is 60,000 BTU/h, or 5 tons.
What size are residential central air conditioners?
Usually 1.5 to 5 tons in half-ton steps. Larger buildings use packaged units of 7.5, 10 tons and up. The right size comes from a load calculation, not the square footage alone.
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