Convert Calories to Petajoules
Convert Calories (cal) to Petajoules (PJ) instantly and accurately.
Conversion Formula
PJ = cal × 4.184000000e-15
About Calories
A calorie (cal) - the thermochemical calorie - is exactly 4.184 J, defined as the heat to raise 1 g of water by 1°C. Standard since 1954. The calorie is the fundamental unit of heat measurement in thermochemistry: glucose combustion releases 669.9 kcal/mol; water vaporisation requires 539.7 cal/g. Bond dissociation energies in quantum chemistry are often quoted in kcal/mol. Note: the dietary Calorie (capital C) on food labels is 1 kcal = 4,184 J - a factor-of-1,000 difference that causes persistent confusion. 1 cal = 4.184 J = 1.163 × 10⁻³ Wh.
About Petajoules
A petajoule (PJ) is 10¹⁵ J - the national energy policy scale. IEA reports primary energy in PJ/year: Sweden ~600 PJ; Germany ~12,500 PJ; the United States ~93,000 PJ. World total primary energy supply is ~605,000 PJ = 605 EJ. The 1883 Krakatoa eruption released ~200 PJ ≈ 48 megatons TNT. A 1-megaton nuclear weapon releases 4.184 PJ. Global annual steel production embeds ~38,000-47,000 PJ of energy. 1 PJ = 10¹⁵ J = 277.78 GWh = 238.85 ktoe = 23.88 ktoe.
Quick Reference Table
| Calories (cal) | Petajoules (PJ) |
|---|---|
| 1 cal | 4.184 × 10-15 PJ |
| 2 cal | 8.368 × 10-15 PJ |
| 5 cal | 2.092 × 10-14 PJ |
| 10 cal | 4.184 × 10-14 PJ |
| 25 cal | 1.046 × 10-13 PJ |
| 50 cal | 2.092 × 10-13 PJ |
| 100 cal | 4.184 × 10-13 PJ |