Convert Kilotons of TNT to Megajoules

Convert Kilotons of TNT (kt(TNT)) to Megajoules (MJ) instantly and accurately.

Kilotons of TNT (kt(TNT))
Megajoules (MJ)

Conversion Formula

MJ = kt(TNT) × 4184000

About Kilotons of TNT

A kiloton of TNT (kt(TNT)) = 10³ tons of TNT = exactly 4.184 TJ. It is the standard unit for sub-megaton nuclear weapon yields. Hiroshima's Little Boy: ~12-18 kt; Nagasaki's Fat Man: ~19-23 kt. The W88 warhead (Trident II) is ~475 kt; the W76 is ~100 kt. The Beirut port explosion (2020): estimated 0.5-1.1 kt. A magnitude 5.0 earthquake releases ~0.5-2 kt of seismic energy. A kiloton blast creates a fireball ~90-100 m radius and a lethal thermal radius of ~1-2 km. 1 kt(TNT) = 4.184 TJ = 1,162.8 MWh.

About Megajoules

A megajoule (MJ) is 10⁶ J - the scale of fuel combustion in vehicles and kinetic energy of road traffic. Energy content: 1 L diesel ~34.9 MJ; 1 L petrol ~32.2 MJ. A 1,500 kg car at 100 km/h has KE = ½ × 1,500 × 27.78² ≈ 0.579 MJ; at 200 km/h it carries 2.31 MJ - explaining crash severity's quadratic speed dependence. A 60 kWh EV battery stores 60 × 3.6 = 216 MJ. Detonation of 1 kg TNT releases 4.184 MJ. Adults at rest metabolise ~6-9 MJ/day. 1 MJ = 10⁶ J = 239.0 kcal = 0.27778 kWh = 947.8 BTU.

Quick Reference Table

Kilotons of TNT (kt(TNT))Megajoules (MJ)
1 kt(TNT)4184000 MJ
2 kt(TNT)8368000 MJ
5 kt(TNT)20920000 MJ
10 kt(TNT)41840000 MJ
25 kt(TNT)104600000 MJ
50 kt(TNT)209200000 MJ
100 kt(TNT)418400000 MJ

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