Convert Ergs to Kilocalories
Convert Ergs (erg) to Kilocalories (kcal) instantly and accurately.
Conversion Formula
kcal = erg × 2.390057361e-11
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 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.
Quick Reference Table
| Ergs (erg) | Kilocalories (kcal) |
|---|---|
| 1 erg | 2.39 × 10-11 kcal |
| 2 erg | 4.78 × 10-11 kcal |
| 5 erg | 1.195 × 10-10 kcal |
| 10 erg | 2.39 × 10-10 kcal |
| 25 erg | 5.975 × 10-10 kcal |
| 50 erg | 1.195 × 10-9 kcal |
| 100 erg | 2.39 × 10-9 kcal |