Convert Millijoules to Kilotons of TNT
Convert Millijoules (mJ) to Kilotons of TNT (kt(TNT)) instantly and accurately.
Conversion Formula
kt(TNT) = mJ × 2.390057361e-16
About Millijoules
A millijoule (mJ) is 10⁻³ J - the scale of surgical lasers, spark ignition, and the kinetic energy of small everyday objects. Nd:YAG lasers for ophthalmology and tattoo removal deliver 10-200 mJ per pulse. The minimum spark energy to ignite methane-air is ~0.29 mJ; an automotive spark plug discharges 30-60 mJ per cycle. A 2 g mosquito flying at 1 m/s has kinetic energy ½ × 0.002 × 1² = 1 mJ. Electrocautery monopolar pulses deliver 50-500 mJ to coagulate blood vessels. 1 mJ = 10⁻³ J = 0.2390 cal.
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
| Millijoules (mJ) | Kilotons of TNT (kt(TNT)) |
|---|---|
| 1 mJ | 2.39 × 10-16 kt(TNT) |
| 2 mJ | 4.78 × 10-16 kt(TNT) |
| 5 mJ | 1.195 × 10-15 kt(TNT) |
| 10 mJ | 2.39 × 10-15 kt(TNT) |
| 25 mJ | 5.975 × 10-15 kt(TNT) |
| 50 mJ | 1.195 × 10-14 kt(TNT) |
| 100 mJ | 2.39 × 10-14 kt(TNT) |