Horsepower to Ergs Per Second (hp to erg/s)
1 horsepower equals 7,456,998,716 ergs per second (rounded).
How to convert horsepower to ergs per second
To convert horsepower to ergs per second, multiply the number of horsepower by 7,456,998,716. The factor is rounded to 10 significant digits. To go the other way, multiply ergs per second by 1.34102209×10⁻¹⁰ (rounded).
ergs per second = horsepower × 7,456,998,716
Example: 10 horsepower = 74,569,987,158 ergs per second.
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
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
Erg Per Second (erg/s)
Exactly 10⁻⁷ watts, the CGS unit of power. Used for the luminosity of stars.
Erg per second is simply the erg divided by the second, a rate of energy use that forms the power unit of the centimeter-gram-second system. In base units it is 1 g cm2/s3, and it equals 10 to the power minus 7 watt, a tenth of a microwatt.
The system goes back to the committee of the British Association for the Advancement of Science in 1873, which recommended the centimeter, gram and second as fundamental units. Power in this system never received a special name, which is why the awkward compound form remained in use.
One watt is therefore 10 million erg/s. The small size means everyday machines look huge in these terms, and the unit is mostly met where very large outputs are discussed, such as luminosities in astrophysics, where Gaussian CGS units are still common.
1 erg per second = 1×10⁻⁷ watts (exactly).
Sources: Wikipedia: Centimetre-gram-second system of units; Wikipedia: Erg (unit); NIST SP 811, Appendix B.8 conversion factors
Related conversions
- Ergs per second to horsepower (reverse)
- Horsepower to watts
- Horsepower to kilowatts
- Horsepower to megawatts
- Horsepower to gigawatts
- Horsepower to metric horsepower
- Horsepower to BTU per hour
- Horsepower to milliwatts
- Horsepower to electrical horsepower
- Horsepower to foot-pounds per second
- Horsepower to tons of refrigeration
- Horsepower to kilocalories per hour
- Horsepower to calories per second
- Watts to ergs per second
- Kilowatts to ergs per second
See all power units.