Convert Joules to Kilotons of TNT
Convert Joules (J) to Kilotons of TNT (kt(TNT)) instantly and accurately.
Conversion Formula
kt(TNT) = J × 2.390057361e-13
About Joules
The joule (J) is the SI unit of energy, defined as one newton acting through one metre (1 J = 1 N·m = 1 kg·m²/s²). Named after James Prescott Joule, whose 1840s paddle-wheel experiments established the mechanical equivalent of heat (~4.15 J = 1 calorie). One joule is modest: it lifts a 100 g apple by 1 m, heats 0.239 mL of water by 1°C, or powers a 1 W LED for 1 second. Daily adult resting metabolism is ~6-9 MJ. 1 J = 1 W·s = 0.23901 cal = 9.4782 × 10⁻⁴ BTU = 2.7778 × 10⁻⁷ kWh.
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.
Quick Reference Table
| Joules (J) | Kilotons of TNT (kt(TNT)) |
|---|---|
| 1 J | 2.39 × 10-13 kt(TNT) |
| 2 J | 4.78 × 10-13 kt(TNT) |
| 5 J | 1.195 × 10-12 kt(TNT) |
| 10 J | 2.39 × 10-12 kt(TNT) |
| 25 J | 5.975 × 10-12 kt(TNT) |
| 50 J | 1.195 × 10-11 kt(TNT) |
| 100 J | 2.39 × 10-11 kt(TNT) |