Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 kJ | 1e-06 MJ | |
| 0.01 kJ | 1e-05 MJ | |
| 0.1 kJ | 0.0001 MJ | |
| 1 kJ | 0.001 MJ | |
| 5 kJ | 0.005 MJ | |
| 10 kJ | 0.01 MJ | |
| 50 kJ | 0.05 MJ | |
| 100 kJ | 0.1 MJ | |
| 1000 kJ | 1 MJ |
Formula: Megajoule = Kilojoule × 0.001
Multiply any kilojoule value by 0.001 to get megajoule.
Reverse: Kilojoule = Megajoule × 1000
Common kilojoule values — factor: 1 kJ = 0.001 MJ
| Kilojoule (kJ) | Megajoule (MJ) | Context |
|---|---|---|
| 0.001 kJ | 1.000e-06 MJ | 1 J |
| 0.01 kJ | 1.000e-05 MJ | 10 J |
| 0.1 kJ | 0.0001 MJ | 100 J |
| 1 kJ | 0.001 MJ | 1 kJ |
| 4.184 kJ | 0.004184 MJ | 1 kcal |
| 10 kJ | 0.01 MJ | 10 kJ |
| 100 kJ | 0.1 MJ | 100 kJ |
| 1,000 kJ | 1 MJ | 1 MJ |
| 3,600 kJ | 3.6 MJ | 1 kWh |
| 1e+04 kJ | 10 MJ | 10 MJ |
| 1e+05 kJ | 100 MJ | 100 MJ |
| 1e+06 kJ | 1,000 MJ | 1 GJ |
| 1e+08 kJ | 1e+05 MJ | 100 GJ |
| 1.000e+10 kJ | 1e+07 MJ | 10 TJ |
| 1.000e+12 kJ | 1.000e+09 MJ | 1 PJ |
kJ ÷ 1,000 = MJ. Exact.
Simple mega prefix.
MJ × 1,000 = kJ.
Labels food energy in kJ for metric-market nutritional information.
Calculates reaction heat, enthalpy changes, and process energy in kJ.
Measures athlete metabolic rate and substrate oxidation in kJ.
Teaches heat transfer, steam tables, and engine cycles using kJ.
Prescribes energy intake using kJ in countries using metric labels.
Calculates heat duty for reactors, heat exchangers, and distillation in kJ.
The kilojoule (kJ) equals 1,000 joules and is the practical energy unit for food, chemistry, and heating applications in metric countries. Food energy labels in Australia, Europe, and most of the world use kilojoules.
A dietary calorie (kcal) equals 4.184 kJ. A can of soda contains about 600 kJ. The specific heat of water (4.184 kJ/kg·°C) means heating 1 liter of water by 1°C requires 4.184 kJ.
Interesting fact: An average adult needs about 8,000-10,000 kJ (2,000-2,400 kcal) per day. Running a marathon burns approximately 12,500 kJ.
The megajoule (MJ) equals 1,000,000 joules and is used for large-scale energy measurements in engineering, transportation, and industrial processes.
One liter of petrol contains about 34 MJ of chemical energy. A bolt of lightning releases about 1-5 MJ. An adult's daily food intake is roughly 8-10 MJ. Electric vehicle batteries are typically rated at 40-100 MJ (11-28 kWh).
Interesting fact: The kinetic energy of a 1,000 kg car traveling at 100 km/h is about 0.385 MJ. TNT explosive releases about 4.6 MJ per kilogram when detonated.
Converting kilojoule to megajoule is common across energy, nutrition, engineering, and science. Different sectors use different energy units — joules in physics, kcal in nutrition, kWh in electricity, and BTU in HVAC — making accurate conversion essential for cross-disciplinary work and international comparisons.
Quick reference: 5 kJ = 0.005 MJ and 10 kJ = 0.01 MJ. Reverse: 1 MJ = 1000 kJ. Exact factor: 1 kJ = 0.001 MJ.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.