Convert Kilotons of TNT to Gigajoules

Convert Kilotons of TNT (kt(TNT)) to Gigajoules (GJ) instantly and accurately.

Kilotons of TNT (kt(TNT))
Gigajoules (GJ)

Conversion Formula

GJ = kt(TNT) × 4184

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 Gigajoules

A gigajoule (GJ) is 10⁹ J - the scale of fossil-fuel commodity volumes. One barrel of crude oil contains ~5.80 GJ; one metric tonne of hard coal ~29.3 GJ. Canadian energy bills express household consumption in GJ: average Canadian households use ~100-130 GJ/year. A 1 GW power plant at 33% efficiency burns ~10.9 GJ/h of fuel to generate 1 GWh = 3.6 GJ of electricity. Detonation of 1 tonne of TNT releases 4.184 GJ. 1 GJ = 10⁹ J = 277.78 kWh = 947,817 BTU = 9.4782 therms.

Quick Reference Table

Kilotons of TNT (kt(TNT))Gigajoules (GJ)
1 kt(TNT)4184 GJ
2 kt(TNT)8368 GJ
5 kt(TNT)20920 GJ
10 kt(TNT)41840 GJ
25 kt(TNT)104600 GJ
50 kt(TNT)209200 GJ
100 kt(TNT)418400 GJ

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