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# How Many BTUs To Cool a Room

How Many BTUs To Cool a Room?

A 115 volt, 10,000 BTU Window Air Conditioning unit is capable of cooling a 500 square foot room without much strain on the unit. So a good rule of thumb is 20 BTUs per square foot.
So for example, if your room to be cooled is approximately 10 x 25 you would have a 250 square foot space to cool, and would require a 5,000 BTU unit to handle the job.

Caution when choosing a unit not to “way overdo” the BTU requirement. Many will buy a much larger unit thinking they are doing themselves a favor. To much cooling can lead to environmental hazards from moisture build up (such as mold), and place an unnecessary draw on your utility bill.

Whenever purchasing an appliance, be sure to review the EnergyStar rating on the label if the unit is EnergyStar rated. This yellow label will estimate the annual cost of operating your unit based on the now 2007 National Average for Electricity Consumption that’s recently been published.

Length of Room x Width of Room [in feet] = Area

(Area x 30) + 2000 = BTUs you need

• If the room is shaded, reduce the BTUs by 10%.
• If the room is very sunny, increase the BTUs by 10%.
• If you plan on placing the air conditioning unit in your kitchen, add 4,000 BTUs.
• If more than two people will regularly be in the room (e.g., an office), add 600 BTUs per person.

BTU Calculator Air Conditioner Calculator

Square Feet of Room to be Cooled
How is the Room Insulation? Is the Room Very Sunny?   Is This Air Conditioner for the Kitchen? Total BTU

100 to 150   Excellent yes   yes 11260.000000000002 BTU (3300 watts)
100 to 150   Excellent no   no  6600.000000000001 BTU (1934 watts)
100 to 150   Excellent yes   no 7260.000000000002 BTU (2128 watts)
100 to 150   Excellent no   yes  10600 BTU (3107 watts)
100 to 150   Very Good yes   yes  11920 BTU (3494 watts)
100 to 150   Very Good no   no 7200 BTU (2110 watts)
100 to 150   Very Good yes   no 7920.000000000001 BTU (2321 watts)
100 to 150   Very Good no   yes  11200 BTU (3283 watts)
100 to 150   Average yes   yes  12580.000000000002 BTU (3687 watts)
100 to 150   Average no   no  7800 BTU (2286 watts)
100 to 150   Average yes   no 8580.000000000002 BTU (2515 watts)
100 to 150   Average no   yes  11800 BTU (3458 watts)
100 to 150   Poor yes   yes 13240 BTU (3880 watts)
100 to 150   Poor no   no 8400 BTU (2462 watts)
100 to 150   Poor yes   no 9240 BTU (2708 watts)
100 to 150   Poor no   yes  12400 BTU (3634 watts)
100 to 150   None yes   yes 13900.000000000002 BTU (4074 watts)
100 to 150   None no   no  9000 BTU (2638 watts)
100 to 150   None yes   no  9900.000000000002 BTU (2902 watts)
100 to 150   None no   yes  13000 BTU (3810 watts)
150 to 250   Excellent yes   yes  12470.000000000002 BTU (3655 watts)
150 to 250   Excellent no   no  7700.000000000001 BTU (2257 watts)
150 to 250   Excellent yes   no  8470.000000000002 BTU (2482 watts)
150 to 250   Excellent no   yes 11700 BTU (3429 watts)
150 to 250   Very Good yes   yes  13240 BTU (3880 watts)
150 to 250   Very Good no   no 8400 BTU (2462 watts)
150 to 250   Very Good yes   no  9240 BTU (2708 watts)
150 to 250   Very Good no   yes  12400 BTU (3634 watts)
150 to 250   Average yes   yes 14010.000000000002 BTU (4106 watts)
150 to 250   Average no   no 9100 BTU (2667 watts)
150 to 250   Average yes   no  10010.000000000002 BTU (2934 watts)
150 to 250   Average no   yes 13100 BTU (3839 watts)
150 to 250   Poor yes   yes  14780 BTU (4332 watts)
150 to 250   Poor no   no 9800 BTU (2872 watts)
150 to 250   Poor yes   no 10780 BTU (3159 watts)
150 to 250   Poor no   yes  13800 BTU (4045 watts)
150 to 250   None yes   yes  15550.000000000002 BTU (4557 watts)
150 to 250   None no   no  10500 BTU (3077 watts)
150 to 250   None yes   no 11550.000000000002 BTU (3385 watts)
150 to 250   None no   yes  14500 BTU (4250 watts)
350 to 400   Excellent yes   yes  14890 BTU (4364 watts)
350 to 400   Excellent no   no  9900 BTU (2902 watts)
350 to 400   Excellent yes   no 10890 BTU (3192 watts)
350 to 400   Excellent no   yes  13900 BTU (4074 watts)
350 to 400   Very Good yes   yes  15880 BTU (4654 watts)
350 to 400   Very Good no   no  10800 BTU (3165 watts)
350 to 400   Very Good yes   no  11880 BTU (3482 watts)
350 to 400   Very Good no   yes  14800 BTU (4338 watts)
350 to 400   Average yes   yes  16870 BTU (4944 watts)
350 to 400   Average no   no  11700 BTU (3429 watts)
350 to 400   Average yes   no  12870 BTU (3772 watts)
350 to 400   Average no   yes  15700 BTU (4601 watts)
350 to 400   Poor yes   yes  17860 BTU (5234 watts)
350 to 400   Poor no   no  12600 BTU (3693 watts)
350 to 400   Poor yes   no 13860 BTU (4062 watts)
350 to 400   Poor no   yes  16600 BTU (4865 watts)
350 to 400   None yes   yes 18850 BTU (5525 watts)
350 to 400   None no   no  13500 BTU (3957 watts)
350 to 400   None yes   no  14850 BTU (4352 watts)
350 to 400   None no   yes  17500 BTU (5129 watts)
400 to 450   Excellent yes   yes  16100.000000000002 BTU (4719 watts)
400 to 450   Excellent no   no 11000 BTU (3224 watts)
400 to 450   Excellent yes   no 12100.000000000002 BTU (3546 watts)
400 to 450   Excellent no   yes  15000 BTU (4396 watts)
400 to 450   Very Good yes   yes  17200 BTU (5041 watts)
400 to 450   Very Good no   no  12000 BTU (3517 watts)
400 to 450   Very Good yes   no  13200 BTU (3869 watts)
400 to 450   Very Good no   yes  16000 BTU (4689 watts)
400 to 450   Average yes   yes  18300 BTU (5363 watts)
400 to 450   Average no   no  13000 BTU (3810 watts)
400 to 450   Average yes   no  14300 BTU (4191 watts)
400 to 450   Average no   yes 17000 BTU (4982 watts)
400 to 450   Poor yes   yes  19400 BTU (5686 watts)
400 to 450   Poor no   no  14000 BTU (4103 watts)
400 to 450   Poor yes   no  15399.999999999998 BTU (4513 watts)
400 to 450   Poor no   yes  18000 BTU (5275 watts)
400 to 450   None yes   yes  20500 BTU (6008 watts)
400 to 450   None no   no  15000 BTU (4396 watts)
400 to 450   None yes   no  16500 BTU (4836 watts)
400 to 450   None no   yes 19000 BTU (5569 watts)
450 to 550   Excellent yes   yes  18520.000000000004 BTU (5428 watts)
450 to 550   Excellent no   no 13200.000000000002 BTU (3869 watts)
450 to 550   Excellent yes   no  14520.000000000004 BTU (4256 watts)
450 to 550   Excellent no   yes  17200 BTU (5041 watts)
450 to 550   Very Good yes   yes 19840 BTU (5815 watts)
450 to 550   Very Good no   no  14400 BTU (4220 watts)
450 to 550   Very Good yes   no 15840.000000000002 BTU (4642 watts)
450 to 550   Very Good no   yes  18400 BTU (5393 watts)
450 to 550   Average yes   yes  21160.000000000004 BTU (6202 watts)
450 to 550   Average no   no  15600 BTU (4572 watts)
450 to 550   Average yes   no 17160.000000000004 BTU (5029 watts)
450 to 550   Average no   yes  19600 BTU (5744 watts)
450 to 550   Poor yes   yes 22480 BTU (6589 watts)
450 to 550   Poor no   no  16800 BTU (4924 watts)
450 to 550   Poor yes   no  18480 BTU (5416 watts)
450 to 550   Poor no   yes  20800 BTU (6096 watts)
450 to 550   None yes   yes  23800.000000000004 BTU (6975 watts)
450 to 550   None no   no  18000 BTU (5275 watts)
450 to 550   None yes   no  19800.000000000004 BTU (5803 watts)
450 to 550   None no   yes 22000 BTU (6448 watts)
550 to 700   Excellent yes   yes 20940.000000000004 BTU (6137 watts)
550 to 700   Excellent no   no  15400.000000000002 BTU (4513 watts)
550 to 700   Excellent yes   no  16940.000000000004 BTU (4965 watts)
550 to 700   Excellent no   yes  19400 BTU (5686 watts)
550 to 700   Very Good yes   yes  22480 BTU (6589 watts)
550 to 700   Very Good no   no  16800 BTU (4924 watts)
550 to 700   Very Good yes   no 18480 BTU (5416 watts)
550 to 700   Very Good no   yes  20800 BTU (6096 watts)
550 to 700   Average yes   yes 24020.000000000004 BTU (7040 watts)
550 to 700   Average no   no  18200 BTU (5334 watts)
550 to 700   Average yes   no  20020.000000000004 BTU (5868 watts)
550 to 700   Average no   yes  22200 BTU (6506 watts)
550 to 700   Poor yes   yes  25560 BTU (7491 watts)
550 to 700   Poor no   no  19600 BTU (5744 watts)
550 to 700   Poor yes   no  21560 BTU (6319 watts)
550 to 700   Poor no   yes 23600 BTU (6917 watts)
550 to 700   None yes   yes  27100.000000000004 BTU (7943 watts)
550 to 700   None no   no  21000 BTU (6155 watts)
550 to 700   None yes   no 23100.000000000004 BTU (6770 watts)
550 to 700   None no   yes 25000 BTU (7327 watts)
700 to 1000   Excellent yes   yes  25780 BTU (7556 watts)
700 to 1000   Excellent no   no  19800 BTU (5803 watts)
700 to 1000   Excellent yes   no  21780 BTU (6383 watts)
700 to 1000   Excellent no   yes  23800 BTU (6975 watts)
700 to 1000   Very Good yes   yes  27760 BTU (8136 watts)
700 to 1000   Very Good no   no  21600 BTU (6331 watts)
700 to 1000   Very Good yes   no  23760 BTU (6964 watts)
700 to 1000   Very Good no   yes  25600 BTU (7503 watts)
700 to 1000   Average yes   yes  29740 BTU (8716 watts)
700 to 1000   Average no   no  23400 BTU (6858 watts)
700 to 1000   Average yes   no 25740 BTU (7544 watts)
700 to 1000   Average no   yes  27400 BTU (8030 watts)
700 to 1000   Poor yes   yes  31720 BTU (9297 watts)
700 to 1000   Poor no   no 25200 BTU (7386 watts)
700 to 1000   Poor yes   no  27720 BTU (8124 watts)
700 to 1000   Poor no   yes  29200 BTU (8558 watts)
700 to 1000   None yes   yes  33700 BTU (9877 watts)
700 to 1000   None no   no  27000 BTU (7913 watts)
700 to 1000   None yes   no  29700 BTU (8705 watts)
700 to 1000   None no   yes  31000 BTU (9086 watts)