Convert Megatons of TNT to Kilocalories
Convert Megatons of TNT (Mt(TNT)) to Kilocalories (kcal) instantly and accurately.
Conversion Formula
kcal = Mt(TNT) × 1000000000000
About Megatons of TNT
A megaton of TNT (Mt(TNT)) = 10⁶ tons of TNT = exactly 4.184 PJ. The Soviet Tsar Bomba (1961) yielded ~50 Mt - the largest human-made explosion ever, with a fireball 8 km in diameter. Castle Bravo (1954) yielded ~15 Mt, 2.5× its 6 Mt design yield. Modern thermonuclear warheads typically range from 0.1-1.2 Mt. The 2011 Tōhoku earthquake released ~500 Mt in seismic energy. The Krakatoa 1883 eruption released ~200 Mt; Tambora 1815 ~33,000 Mt. 1 Mt(TNT) = 4.184 PJ = 1,162,800 MWh.
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
| Megatons of TNT (Mt(TNT)) | Kilocalories (kcal) |
|---|---|
| 1 Mt(TNT) | 1 × 1012 kcal |
| 2 Mt(TNT) | 2 × 1012 kcal |
| 5 Mt(TNT) | 5 × 1012 kcal |
| 10 Mt(TNT) | 1 × 1013 kcal |
| 25 Mt(TNT) | 2.5 × 1013 kcal |
| 50 Mt(TNT) | 5 × 1013 kcal |
| 100 Mt(TNT) | 1 × 1014 kcal |