Convert Ergs to Horsepower-Hours
Convert Ergs (erg) to Horsepower-Hours (hp·h) instantly and accurately.
Conversion Formula
hp·h = erg × 3.725061360e-14
About Ergs
An erg is the CGS unit of energy - the work done by one dyne through one centimetre - exactly 10⁻⁷ J. Despite SI adoption, the erg persists in astrophysics: the Sun's luminosity is 3.828 × 10³³ erg/s; gamma-ray burst isotropic energies are quoted in units of 10⁵¹ erg ('one foe'). Surface tension of water is 72.8 dyn/cm; the work to create 1 cm² of new water-air interface is 72.8 erg. Earthquake seismic moment M₀ is in dyn·cm = erg; the 2004 Boxing Day earthquake had M₀ ≈ 10²³ J = 10³⁰ erg. 1 erg = 10⁻⁷ J = 624.15 eV.
About Horsepower-Hours
A horsepower-hour (hp·h) is the energy from one mechanical horsepower (745.6999 W) for one hour - exactly 2,684,519.54 J ≈ 2.685 MJ. James Watt coined the horsepower to compare his steam engines with mine horses; billing in hp·h preceded the kilowatt-hour tariff. The metric horsepower (PS = 75 kgf·m/s = 735.499 W) gives a slightly smaller metric-hp·h = 2,647,795 J, used in European and Japanese engine datasheets. Today the hp·h appears in marine engineering logs, mining energy accounting, and vintage industrial equipment. 1 hp·h = 2.6845 MJ = 0.74570 kWh = 641.19 kcal.
Quick Reference Table
| Ergs (erg) | Horsepower-Hours (hp·h) |
|---|---|
| 1 erg | 3.725 × 10-14 hp·h |
| 2 erg | 7.45 × 10-14 hp·h |
| 5 erg | 1.863 × 10-13 hp·h |
| 10 erg | 3.725 × 10-13 hp·h |
| 25 erg | 9.313 × 10-13 hp·h |
| 50 erg | 1.863 × 10-12 hp·h |
| 100 erg | 3.725 × 10-12 hp·h |