Summary: Btu to joule, watt, erg, foot pounds conversion factors and data on British thermal units

 Btu Conversions
Put simply, one British Thermal Unit [Btu] is the amount of heat required to raise the temperature of
1 pound [ lb.] of water 1 degree Fahrenheit.
The Fifth International Conference on the Properties of Steam (London, July 1956) defined the International Table calorie as 4.1868 joule.
Therefore the exact conversion factor for the International Table British thermal unit (Btu) is 1.05505585262 kJ.
The thermochemical Btu is based on the thermochemical calorie which equals 4.184 joule exactly.

Note that reference is often made to the calorie when in actual fact the kilocalorie (also called Calorie, large calorie or kilogram calorie) is meant. (1 kilocalorie = 1000 calories)
 These units multiplied by ...... ..this factor will... ..convert to these units. Btu 1.06E+10 ergs Btu 778.3 foot-lbs Btu 252 gram-calories Btu 0.0003931 horsepower-hrs Btu (39 ºF) 1059.67 joules (J) Btu (59 ºF) 1054.8 joules Btu (60 ºF) 1054.68 joules Btu (international table) 1055.056 joules Btu (thermochemical) 1054.35 joules Btu 0.252 kilogram-calories Btu 107.5 kilogram-metres Btu 0.0002928 kilowatt-hrs Btu /hr 0.2162 foot-pounds/sec Btu /hr 0.07 gram-cal/sec Btu /hr 0.0003929 horsepower-hrs Btu (int)/hr 0.2930711 watts Btu (thermo)/hr 0.2928751 watts Btu /min 12.96 foot-lbs/sec Btu /min 0.02356 horsepower Btu /min 0.01757 kilowatts Btu(thermo)/min 17.5725 watts Btu (int)/sec 1055.056 watts Btu (thermo)/sec 1054.35 watts Btu (thermo) /sq. ft. min 189.1489 watts /sq. metre Btu (int) /sq. ft. sec 11356.53 watts /sq. metre Btu (thermo) /sq. ft. sec 11348.93 watts /sq. metre Btu (thermo) /sq. in. sec 1.634246E+06 watts /sq. metre Btu (int) ft./hr sq.ft. ºF 1.730735 watt per metre kelvin Btu (thermo) ft./hr sq.ft. ºF 1.729577 watt per metre kelvin Btu (int) in /hr sq.ft. ºF 0.1442279 watt per metre kelvin Btu (thermo) in./hr sq.ft. ºF 0.1441314 watt per metre kelvin Btu (int) in /sec sq.ft. ºF 519.2204 watt per metre kelvin Btu (thermo) in./hr sq.ft. ºF 518.8732 watt per metre kelvin Btu (int) per cu. ft. 37258.95 joule per cu. metre Btu (thermo) per cu. ft. 37234.03 joule per cu. metre Btu (int) per ºF 1899.101 joule per kelvin Btu (thermo) per ºF 1897.83 joule per kelvin Btu (int) per ºRankine 1899.101 joule per kelvin Btu (thermo) per ºR 1897.83 joule per kelvin Btu (int /cu.ft. ºF 67066.07 joule per cu. metre kelvin Btu (int) /hr sq.ft. ºF 5.678263 watt per sq. metre kelvin Btu (thermo) /hr sq.ft. ºF 5.674466 watt per sq. metre kelvin Btu (int) /sec sq.ft. ºF 20441.75 watt per sq. metre kelvin Btu (thermo) /sec sq.ft. ºF 20428.08 watt per sq. metre kelvin Btu (int) /lb 2326 joule per kg. Btu (thermo) /lb 2324.444 joule per kg. Btu (int) /lb 0.64616 watts per kilogram Btu (int) /lb 0.55498 kilocalorie per kilogram Btu (int) /lb. ºF 4186.8 joul per kg kelvin Btu (thermo) /lb. ºF 4184 joul per kg kelvin Btu (int) /lb. ºRankine 4186.8 joul per kg kelvin Btu (thermo) /lb. ºR 4184 joul per kg kelvin Btu (int) /sq. ft 11356.53 joul per sq. metre Btu (thermo) /sq. ft. 11348.93 joul per sq. metre Btu (int) /sq. ft. hr 3.154591 watt per sq. metre Btu (thermo) /sq. ft. hr 3.152481 watt per sq. metre ~~~~ ~~~~ ~~~~ calorie, gram (mean) 0.00396832 Btu (mean) ~~~~ ~~~~ ~~~~ ergs 9.48E-11 Btu ergs/sec 5.69E-06 Btu/min ~~~~ ~~~~ ~~~~ foot-pounds 0.001286 Btu foot-pounds/min 0.001286 Btu/min foot-pounds/sec 4.6263 Btu/hr foot-pounds/sec 0.07717 Btu/min ~~~~ ~~~~ ~~~~ gram-calories 0.0039683 Btu gram-calories/sec 14.286 Btu/hr gram-calories 9.30E-08 Btu ~~~~ ~~~~ ~~~~ horsepower 42.44 Btu/min horsepower (boiler) 33479 Btu/hr horsepower-hrs 2547 Btu ~~~~ ~~~~ ~~~~ joules 9.48E-04 Btu ~~~~ ~~~~ ~~~~ kilogram-calories 3.968 Btu kilogram-metres 9.29E-03 Btu kilowatts 56.92 Btu/min kilowatt-hrs 3413 Btu ~~~~ ~~~~ ~~~~ tons refrigeration 12000 Btu per hour ~~~~ ~~~~ ~~~~ watts 3.4129 Btu/hr watts 0.05688 Btu/min watts (absolute) 0.056884 Btu (mean)/min watt-hours 3.413 Btu These units multiplied by ...... ..this factor will... ..convert to these units.

For metric conversions go to a unit starting with -
a b c d e f g h i j k l m n o p q r s t u v w y

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