A kilowatt (\(kW\)) is a unit of power in the International System of Units (SI) equal to 1,000 joules per second. It is widely used to rate electrical equipment, motors, and heating elements. In the United States, many commercial‑ and residential‑scale power specifications are still expressed in kilowatts because the metric system is standard for engineering calculations.
Understanding BTU per hour (BTU/hr)
The British Thermal Unit per hour (\(\text{BTU/hr}\)) measures the rate of heat transfer. One BTU is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. When expressed per hour, it becomes a power rating commonly used for HVAC systems, furnaces, and water heaters in the U.S.
Practical Applications of the Conversion
Designing HVAC equipment: engineers often need to translate a motor’s electrical rating (kW) into the heat‑output rating (BTU/hr) of a blower or compressor.
Energy‑billing comparisons: utilities may quote rates in BTU while customers think in kilowatts, so a reliable conversion helps compare costs.
Industrial process control: many thermal processes are specified in BTU/hr, yet the driving electric motors are rated in kW.
Kilowatt to BTU per hour Conversion Reference Table
Kilowatt (kW)
BTU per hour (BTU/hr)
0.1
341.2142
0.5
1706.0712
1.0
3412.1425
2.0
6824.2849
5.0
17060.7123
10.0
34121.4245
20.0
68242.849
50.0
170607.1225
100.0
341214.245
500.0
1.7061e+06
1000.0
3.4121e+06
Step‑by‑Step Conversion Example
Convert 10 kW to BTU/hr using the exact factor 3,412.1424501230076 BTU/hr per kW.
Rounded to a sensible precision, 10 kW ≈ 34,121 BTU/hr.
The factor is the exact number of British Thermal Units transferred in one hour by a power source of one kilowatt. It is derived from the definition of the BTU (1 BTU = 1,055.05585 J) and the SI definition of the watt (1 W = 1 J/s).
Because the factor is defined from fundamental constants, the conversion is exact to the number of digits shown. For most engineering purposes, rounding to three or four significant figures (e.g., 3,412 BTU/hr per kW) is sufficient, even for megawatt‑scale equipment.
"On fait la science avec des faits, comme on fait une maison avec des pierres ; mais une accumulation de faits n'est pas plus une science qu'un tas de pierres n'est une maison." "Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house." — Henri Poincaré (French Mathematician, Theoretical Physicist & Mining Engineer)