Convert Millijoules to Exajoules
Convert Millijoules (mJ) to Exajoules (EJ) instantly and accurately.
Conversion Formula
EJ = mJ × 1.000000000e-21
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 Exajoules
An exajoule (EJ) is 10¹⁸ J - the scale of global energy consumption. World primary energy supply in 2022 was ~580-610 EJ: coal ~160 EJ; oil ~190 EJ; gas ~145 EJ; nuclear ~26 EJ; wind ~8 EJ; solar PV ~8 EJ. Global electricity generation of ~29,000 TWh = 104 EJ. Solar energy incident on Earth's atmosphere is ~5.5 × 10⁶ EJ/year - approximately 9,000× total human demand. Annual fossil fuel combustion releases ~490 EJ/year, producing ~36.8 Gt CO₂. 1 EJ = 10¹⁸ J = 277.78 TWh = 238.85 Mtoe.
Quick Reference Table
| Millijoules (mJ) | Exajoules (EJ) |
|---|---|
| 1 mJ | 1 × 10-21 EJ |
| 2 mJ | 2 × 10-21 EJ |
| 5 mJ | 5 × 10-21 EJ |
| 10 mJ | 1 × 10-20 EJ |
| 25 mJ | 2.5 × 10-20 EJ |
| 50 mJ | 5 × 10-20 EJ |
| 100 mJ | 1 × 10-19 EJ |