Convert Gigajoules to Millijoules
Convert Gigajoules (GJ) to Millijoules (mJ) instantly and accurately.
Conversion Formula
mJ = GJ × 1000000000000
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.
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.
Quick Reference Table
| Gigajoules (GJ) | Millijoules (mJ) |
|---|---|
| 1 GJ | 1 × 1012 mJ |
| 2 GJ | 2 × 1012 mJ |
| 5 GJ | 5 × 1012 mJ |
| 10 GJ | 1 × 1013 mJ |
| 25 GJ | 2.5 × 1013 mJ |
| 50 GJ | 5 × 1013 mJ |
| 100 GJ | 1 × 1014 mJ |