Convert Kilocalories to Terajoules
Convert Kilocalories (kcal) to Terajoules (TJ) instantly and accurately.
Conversion Formula
TJ = kcal × 4.184000000e-9
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 Terajoules
A terajoule (TJ) is 10¹² J - the scale of nuclear yields in the kiloton range and large industrial accidents. One kiloton of TNT = 4.184 TJ; the Hiroshima bomb (15 kt) released ~62.8 TJ. The Halifax Explosion (1917) released ~3 TJ. A 500 MW coal plant consumes ~51.4 TJ/h of thermal input. Daily primary energy of Denmark is ~250-300 TJ; the UK ~3,800 TJ/day. A 1 GW nuclear reactor at 90% capacity factor generates ~77.7 TJ/day. 1 TJ = 10¹² J = 277,778 kWh = 277.78 MWh = 23.88 ktoe.
Quick Reference Table
| Kilocalories (kcal) | Terajoules (TJ) |
|---|---|
| 1 kcal | 4.184 × 10-9 TJ |
| 2 kcal | 8.368 × 10-9 TJ |
| 5 kcal | 2.092 × 10-8 TJ |
| 10 kcal | 4.184 × 10-8 TJ |
| 25 kcal | 1.046 × 10-7 TJ |
| 50 kcal | 2.092 × 10-7 TJ |
| 100 kcal | 4.184 × 10-7 TJ |