BTU to kWh

American air conditioners are rated in BTU per hour — 12,000 BTU, the famous 'one ton' of cooling — while the electrical spec and the metric world read the same machine in kilowatt-hours. The bridge is 0.0002930710702: the exact number of kWh in one British thermal unit, derived from the IT calorie's definition and the mechanical equivalent of heat. A 12,000 BTU unit is 3.52 kWh.

1 BTU = 2.9307107 × 10−4 kWh, and 1 kWh = 3,412.142 BTU. One fixed factor covers the whole range: multiply BTU by 2.9307107 × 10−4. Worked: 1,000 BTU = 0.29307107 kWh; 10,000 BTU = 2.9307107 kWh.

By EnginStack Editorial Team | Reviewed against NIST, BIPM and primary-source documentation About →
BTU
3.51685284 kWh
12,000 BTU = 3.51685284 kWh 12,000 kWh = 40,945,699.5975353 BTU

Verified against NIST Special Publication 811 and BIPM SI definitions. The conversion factor is exact and traceable to the 1959 treaty constants.

BTU to kWh

One BTU is the heat needed to raise one pound of water one degree Fahrenheit, and its exact energy equivalent is fixed by the International Steam Table: 1 BTU = 1055.05585262 joules. Divide by 3,600,000 joules per kilowatt-hour and the factor is exactly 0.0002930710702 kWh. HVAC engineers meet this at every equipment selection — converting a furnace's BTU rating to the kWh it represents, or checking an AC's cooling capacity against its electrical input to find the coefficient of performance.

kWh = BTU × 0.0002930710702
1 BTU = 0.0002930710702 kWh — the IT calorie definition
The factor is exact: 1055.05585262 J ÷ 3,600,000 J/kWh.

Worked Examples

Example 1: Convert the one-ton air-conditioner rating

12,000 × 0.0002930710702 = 3.517 kWh

Example 2: Convert a 5,000 BTU window unit

5,000 × 0.0002930710702 = 1.465 kWh

Example 3: Convert a 60,000 BTU furnace rating

60,000 × 0.0002930710702 = 17.58 kWh

Common BTU to kWh Conversions

BTUkWhContext
1,000 BTU0.293 kWhA small space heater's hourly output.
5,000 BTU1.47 kWhA window AC unit's cooling per hour.
12,000 BTU3.52 kWhThe 'one-ton' AC — 12,000 BTU/hr.
60,000 BTU17.6 kWhA residential furnace's hourly rating.
1,000,000 BTU293 kWhA small industrial boiler's hourly output.

Engineering Context

The kWh to BTU page runs this factor backward. In the energy hub, joules to kWh carries the SI chain (1 BTU = 1055.05585262 J), and watts to kW handles the power side of the same HVAC selection. The furnace BTU story also connects to the temperature family that measures the water the BTU heats.

Almost every figure on this page is really a rate, not a quantity. An air conditioner rated 12,000 BTU is rated 12,000 BTU per hour, which is 3.517 kW of cooling, and 3.517 kWh describes how much heat it moves in one hour. The electricity it consumes is a different number entirely, because a vapor-compression machine moves more heat than the work it is given: a modern unit with a coefficient of performance of 3.5 draws about 1 kW to move 3.5 kW, so its 3.5 kW of cooling costs only 1 kWh per hour of electricity. Keep the rate, the quantity and the efficiency separate or the running cost comes out wrong by a factor of three.

More: kWh to BTU · J to kWh · W to kW · Energy & Power Guide · Energy Hub

Related Unit Converters

kWh to BTU Joules to kWh Watts to Kilowatts Energy & Power Conversion Guide Energy & Power Converters

Frequently Asked Questions

How many kWh is 12,000 BTU?

Exactly 3.5169 kWh. The 12,000 BTU/hr air conditioner rating — called 'one ton' of cooling — is 12,000 × 0.0002930710702 = 3.5169 kWh of heat removed per hour.

Is BTU the same as BTU/hr?

No — they are different quantities. BTU is an amount of energy; BTU/hr is a rate of energy (power). Air conditioners are rated in BTU/hr but colloquially called '12,000 BTU units.' One BTU/hr equals 0.2930710702 watts.

What is a BTU exactly?

One BTU is the heat required to raise one pound of water by one degree Fahrenheit at standard conditions. The International Steam Table fixed its exact energy equivalent at 1055.05585262 joules, from which all modern conversions derive.