Convert Kilocalories to Horsepower-Hours
Convert Kilocalories (kcal) to Horsepower-Hours (hp·h) instantly and accurately.
Conversion Formula
hp·h = kcal × 0.001558565673
About Kilocalories
A kilocalorie (kcal) - the food Calorie (capital C) on US and Canadian nutrition labels - is exactly 4,184 J. WHO recommends ~2,000-2,500 kcal/day for adults. Energy density of nutrients: fat 9 kcal/g, carbohydrate 4 kcal/g, protein 4 kcal/g, ethanol 7 kcal/g. Running at 10 km/h burns ~600-800 kcal/h. Standard free energy of ATP hydrolysis is approximately −7.3 kcal/mol (−30.5 kJ/mol). Pre-SI thermodynamic tables in the US and Japan use kcal/mol for reaction enthalpies. 1 kcal = 4,184 J = 4.184 kJ = 3.968 BTU = 1.163 Wh.
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
| Kilocalories (kcal) | Horsepower-Hours (hp·h) |
|---|---|
| 1 kcal | 0.00155857 hp·h |
| 2 kcal | 0.00311713 hp·h |
| 5 kcal | 0.00779283 hp·h |
| 10 kcal | 0.0155857 hp·h |
| 25 kcal | 0.0389641 hp·h |
| 50 kcal | 0.0779283 hp·h |
| 100 kcal | 0.155857 hp·h |