How do you convert kW to BTU/h?
Multiply the number of kilowatts by 3,412. This is the conversion for comparing an air conditioner sold in Europe, where cooling capacity is quoted in kilowatts, with a North American or Asian model rated in BTU per hour.
kW = BTU/h ÷ 3,412
Cooling capacity in kilowatts and BTU per hour
| 1.5 kW | 5,100 BTU/h |
| 2 kW | 6,800 BTU/h |
| 2.6 kW (9,000 BTU) | 8,900 BTU/h |
| 3.5 kW (12,000 BTU) | 11,900 BTU/h |
| 5 kW | 17,100 BTU/h |
| 5.3 kW (18,000 BTU) | 18,100 BTU/h |
| 7 kW (24,000 BTU) | 23,900 BTU/h |
| 9 kW | 30,700 BTU/h |
| 12 kW | 40,900 BTU/h |
| 15 kW | 51,200 BTU/h |
| 20 kW | 68,200 BTU/h |
Show every value
- 1 kW = 3,412 BTU/h
- 2 kW = 6,824 BTU/h
- 3 kW = 10,236 BTU/h
- 4 kW = 13,649 BTU/h
- 5 kW = 17,061 BTU/h
- 6 kW = 20,473 BTU/h
- 7 kW = 23,885 BTU/h
- 8 kW = 27,297 BTU/h
- 9 kW = 30,709 BTU/h
- 10 kW = 34,121 BTU/h
- 11 kW = 37,534 BTU/h
- 12 kW = 40,946 BTU/h
- 13 kW = 44,358 BTU/h
- 14 kW = 47,770 BTU/h
- 15 kW = 51,182 BTU/h
- 16 kW = 54,594 BTU/h
- 17 kW = 58,006 BTU/h
- 18 kW = 61,419 BTU/h
- 19 kW = 64,831 BTU/h
- 20 kW = 68,243 BTU/h
- 21 kW = 71,655 BTU/h
- 22 kW = 75,067 BTU/h
- 23 kW = 78,479 BTU/h
- 24 kW = 81,891 BTU/h
- 25 kW = 85,304 BTU/h
- 26 kW = 88,716 BTU/h
- 27 kW = 92,128 BTU/h
- 28 kW = 95,540 BTU/h
- 29 kW = 98,952 BTU/h
- 30 kW = 102,364 BTU/h
- 31 kW = 105,776 BTU/h
- 32 kW = 109,189 BTU/h
- 33 kW = 112,601 BTU/h
- 34 kW = 116,013 BTU/h
- 35 kW = 119,425 BTU/h
- 36 kW = 122,837 BTU/h
- 37 kW = 126,249 BTU/h
- 38 kW = 129,661 BTU/h
- 39 kW = 133,074 BTU/h
- 40 kW = 136,486 BTU/h
- 41 kW = 139,898 BTU/h
- 42 kW = 143,310 BTU/h
- 43 kW = 146,722 BTU/h
- 44 kW = 150,134 BTU/h
- 45 kW = 153,546 BTU/h
- 46 kW = 156,959 BTU/h
- 47 kW = 160,371 BTU/h
- 48 kW = 163,783 BTU/h
- 49 kW = 167,195 BTU/h
- 50 kW = 170,607 BTU/h
- 51 kW = 174,019 BTU/h
- 52 kW = 177,431 BTU/h
- 53 kW = 180,844 BTU/h
- 54 kW = 184,256 BTU/h
- 55 kW = 187,668 BTU/h
- 56 kW = 191,080 BTU/h
- 57 kW = 194,492 BTU/h
- 58 kW = 197,904 BTU/h
- 59 kW = 201,316 BTU/h
- 60 kW = 204,728 BTU/h
- 61 kW = 208,141 BTU/h
- 62 kW = 211,553 BTU/h
- 63 kW = 214,965 BTU/h
- 64 kW = 218,377 BTU/h
- 65 kW = 221,789 BTU/h
- 66 kW = 225,201 BTU/h
- 67 kW = 228,613 BTU/h
- 68 kW = 232,026 BTU/h
- 69 kW = 235,438 BTU/h
- 70 kW = 238,850 BTU/h
- 71 kW = 242,262 BTU/h
- 72 kW = 245,674 BTU/h
- 73 kW = 249,086 BTU/h
- 74 kW = 252,498 BTU/h
- 75 kW = 255,911 BTU/h
- 76 kW = 259,323 BTU/h
- 77 kW = 262,735 BTU/h
- 78 kW = 266,147 BTU/h
- 79 kW = 269,559 BTU/h
- 80 kW = 272,971 BTU/h
- 81 kW = 276,383 BTU/h
- 82 kW = 279,796 BTU/h
- 83 kW = 283,208 BTU/h
- 84 kW = 286,620 BTU/h
- 85 kW = 290,032 BTU/h
- 86 kW = 293,444 BTU/h
- 87 kW = 296,856 BTU/h
- 88 kW = 300,268 BTU/h
- 89 kW = 303,681 BTU/h
- 90 kW = 307,093 BTU/h
- 91 kW = 310,505 BTU/h
- 92 kW = 313,917 BTU/h
- 93 kW = 317,329 BTU/h
- 94 kW = 320,741 BTU/h
- 95 kW = 324,153 BTU/h
- 96 kW = 327,566 BTU/h
- 97 kW = 330,978 BTU/h
- 98 kW = 334,390 BTU/h
- 99 kW = 337,802 BTU/h
- 100 kW = 341,214 BTU/h
- 125 kW = 426,518 BTU/h
- 150 kW = 511,821 BTU/h
- 175 kW = 597,125 BTU/h
- 200 kW = 682,428 BTU/h
- 225 kW = 767,732 BTU/h
- 250 kW = 853,035 BTU/h
- 275 kW = 938,339 BTU/h
- 300 kW = 1,023,642 BTU/h
- 325 kW = 1,108,946 BTU/h
- 350 kW = 1,194,250 BTU/h
- 375 kW = 1,279,553 BTU/h
- 400 kW = 1,364,857 BTU/h
- 425 kW = 1,450,160 BTU/h
- 450 kW = 1,535,464 BTU/h
- 475 kW = 1,620,767 BTU/h
- 500 kW = 1,706,071 BTU/h
- 550 kW = 1,876,678 BTU/h
- 600 kW = 2,047,285 BTU/h
- 650 kW = 2,217,892 BTU/h
- 700 kW = 2,388,499 BTU/h
- 750 kW = 2,559,106 BTU/h
- 800 kW = 2,729,713 BTU/h
- 850 kW = 2,900,320 BTU/h
- 900 kW = 3,070,927 BTU/h
- 950 kW = 3,241,535 BTU/h
- 1,000 kW = 3,412,142 BTU/h
- 1,500 kW = 5,118,212 BTU/h
- 2,000 kW = 6,824,283 BTU/h
- 2,500 kW = 8,530,354 BTU/h
- 3,000 kW = 10,236,425 BTU/h
- 3,500 kW = 11,942,496 BTU/h
- 4,000 kW = 13,648,567 BTU/h
- 4,500 kW = 15,354,637 BTU/h
- 5,000 kW = 17,060,708 BTU/h
- 5,500 kW = 18,766,779 BTU/h
- 6,000 kW = 20,472,850 BTU/h
- 6,500 kW = 22,178,921 BTU/h
- 7,000 kW = 23,884,991 BTU/h
- 7,500 kW = 25,591,062 BTU/h
- 8,000 kW = 27,297,133 BTU/h
- 8,500 kW = 29,003,204 BTU/h
- 9,000 kW = 30,709,275 BTU/h
- 9,500 kW = 32,415,346 BTU/h
- 10,000 kW = 34,121,416 BTU/h
The British thermal unit is about 1,055.06 joules in its international thermochemical definition. Per hour, 1 kW equals 3,412.14 BTU/h. Commercial capacities are rounded: a unit advertised at 12,000 BTU actually delivers between 3.4 and 3.6 kW depending on the model. Methodology & sources.
Frequently asked questions
What size air conditioner does a room need?
Allow roughly 100 watts per square metre for a standard, well insulated room, so 2 kW or 7,000 BTU/h for 20 m². Add 20 % for a south-facing wall, a large glazed opening or a top floor under the roof. An oversized unit cools too fast and dehumidifies poorly.
What do 9,000, 12,000 and 18,000 BTU mean?
They are the standard commercial capacities of air conditioners, corresponding to roughly 2.6 kW, 3.5 kW and 5.3 kW. Those steps come from the North American market and spread worldwide, including where the kilowatt is the legal unit.
Where does the phrase one ton of cooling come from?
From the cooling power needed to melt a short ton of ice in 24 hours, that is 12,000 BTU/h or 3.517 kW. The unit dates from when refrigeration was sold as delivered ice, and it outlived the process that produced it.
Is cooling capacity the same as consumption?
No, and this is the costliest confusion. An air conditioner rated 3.5 kW of cooling draws about 1 kW of electricity, the ratio between the two being the coefficient of performance. A good unit shows a SCOP above 4: it returns four times the energy it consumes, because it moves heat rather than producing it.
Are BTU and BTU/h the same thing?
No: one is an energy, the other a power, exactly as kilowatt-hour is to kilowatt. A BTU is a quantity of heat, the amount that raises one pound of water by one degree Fahrenheit. A BTU per hour is a rate of heat flow. An air conditioner sold as 12,000 BTU is really 12,000 BTU/h; the trade shorthand has swallowed the time. On an American boiler the same figure is sometimes written 12 MBH, where M stands for a thousand, not a million.