Kilocalories Per Hour to Horsepower (kcal/h to hp)
1 kilocalorie per hour equals 0.001558565673 horsepower (rounded).
How to convert kilocalories per hour to horsepower
To convert kilocalories per hour to horsepower, multiply the number of kilocalories per hour by 0.001558565673. The factor is rounded to 10 significant digits. To go the other way, multiply horsepower by 641.6155683 (rounded).
horsepower = kilocalories per hour × 0.001558565673
Example: 10 kilocalories per hour = 0.01558565673 horsepower.
Several different horsepower units exist. This site lists mechanical (745.7 W), metric (735.5 W) and electrical (746 W) horsepower separately.
About these units
Kilocalorie Per Hour (kcal/h)
About 1.162 watts, using the thermochemical kilocalorie (the International Table kilocalorie gives 1.163 W).
Heat output and body metabolism were long reckoned in kilocalories, so dividing by hours gave a convenient power unit for stoves, radiators and people. The kilocalorie descends from the calorie that Nicolas Clement introduced in lectures between 1819 and 1824, and the capitalized Calorie for the large unit was proposed by Marcellin Berthelot in 1879 and adopted for nutrition by Wilbur Atwater in 1887.
Which calorie is meant changes the answer. With the thermochemical kilocalorie of 4,184 joules the unit is 4,184 divided by 3,600, about 1.1622 watts, which is the figure used here. With the International Table kilocalorie of 4,186.8 joules it is exactly 1.163 watts, the same number that appears in the definition of the IT calorie as 1.163 milliwatt-hours. Either way, 60 kilocalories per hour is roughly 70 watts.
1 kilocalorie per hour = 1.162222222 watts (approximately).
Sources: Wikipedia: Calorie; NIST SP 811, Appendix B.8
Horsepower (hp)
The mechanical horsepower: 550 foot-pounds per second, about 745.7 watts. James Watt coined it to compare steam engines with draft horses.
Horsepower was a sales pitch before it was a unit. Late in the 18th century the Scottish engineer James Watt adopted the term to compare the output of steam engines with the draft horses they replaced. His 1782 experiments found that a brewery horse could produce 32,400 foot-pounds-force per minute, and in 1783 he and Matthew Boulton standardized the figure at 33,000 foot-pounds-force per minute. Customers could then be told how many horses an engine would replace.
That figure works out to 550 foot-pounds-force per second, or about 745.7 watts: the power needed to lift 550 pounds by one foot in one second. Several cousins exist, including metric horsepower and electrical horsepower, defined as exactly 746 W. Car ratings added more confusion. Early British taxable horsepower was a formula based on bore and cylinder count, not measured output, and American ratings before 1972 used SAE gross brake horsepower, measured without accessories. In the European Union, horsepower may be used only as a supplementary unit under Directive 80/181/EEC, in force from 1 January 2010.
1 horsepower = 745.6998716 watts (approximately).
Sources: Wikipedia: Horsepower; Wikipedia: Metric horsepower
Related conversions
- Horsepower to kilocalories per hour (reverse)
- Kilocalories per hour to watts
- Kilocalories per hour to kilowatts
- Watts to horsepower
- Kilowatts to horsepower
- Megawatts to horsepower
- Gigawatts to horsepower
- Metric horsepower to horsepower
- BTU per hour to horsepower
- Milliwatts to horsepower
- Electrical horsepower to horsepower
- Foot-pounds per second to horsepower
- Tons of refrigeration to horsepower
- Calories per second to horsepower
- Ergs per second to horsepower
See all power units.