BTU to kW Converter

Convert BTU per hour to kilowatts and back — the HVAC sizing conversion, with the rate-vs-energy distinction made plain.

Convert BTU/h ⇄ kW

3.5169 kW
12000 BTU/h = 3.5169 kW

Formula: 12000 BTU/h (BTU/h ÷ 3,412.14) = 3.5169 kW

How the btu to kw conversion works

The conversion is exact: kilowatts = BTU per hour ÷ 3,412.14. One watt equals 3.41214 BTU per hour, so one kilowatt (1,000 watts) equals 3,412.14 BTU/h. Going the other way, BTU/h = kW × 3,412.14.

Rate, not total energy: this page converts a rate — BTU per hour, the figure on air-conditioner and heater nameplates — into kilowatts, also a rate. A bare BTU figure with no time attached is an amount of energy, not a power rating; that conversion is BTU to kWh. If your unit says just “BTU” on a cooling spec, it almost always means BTU/h.

Worked example: a 12,000 BTU/h air conditioner — the classic “1-ton” unit — is 12,000 ÷ 3,412.14 = 3.52 kW of cooling. And a 5 kW heater outputs 5 × 3,412.14 = 17,061 BTU/h. For the reverse energy question, see watts to BTU per hour and BTU to kWh.

Handy benchmarks: 5,000 BTU/h = 1.47 kW, 9,000 BTU/h = 2.64 kW, 12,000 BTU/h = 3.52 kW, 18,000 BTU/h = 5.27 kW and 24,000 BTU/h = 7.03 kW.

btu to kw converter questions

How many BTU per hour are in 1 kW?
Exactly 3,412.14 BTU/h. One watt is 3.41214 BTU/h, and a kilowatt is 1,000 watts, so 1,000 × 3.41214 = 3,412.14 BTU/h.
How do I convert BTU to kW?
Divide BTU per hour by 3,412.14: kW = BTU/h ÷ 3,412.14. So a 12,000 BTU/h air conditioner is 12,000 ÷ 3,412.14 = 3.52 kW. If your figure is total BTU with no time unit, use our BTU to kWh converter instead.
What is 12,000 BTU in kW?
3.52 kW — assuming 12,000 BTU/h, the standard rating for a 1-ton air conditioner. 12,000 ÷ 3,412.14 = 3.5169, rounded to 3.52 kW.
Is BTU the same as BTU/h?
Not quite. A BTU is an amount of energy; BTU/h is a rate — energy per hour — which is what cooling and heating capacity are rated in. Air-conditioner specs that say “12,000 BTU” mean 12,000 BTU/h. This converter works on the BTU/h rate.
How do I convert kW back to BTU?
Multiply by 3,412.14: BTU/h = kW × 3,412.14. Switch the direction above to do it — a 3.5 kW unit is about 11,942 BTU/h.

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Sources & official guidance

Exact power conversion — 1 kW = 3,412.14 BTU/h. BTU figures on appliance specs mean BTU/h unless stated otherwise. See our disclaimer.