Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 MJ | 239.006 cal | |
| 0.01 MJ | 2390.06 cal | |
| 0.1 MJ | 23900.6 cal | |
| 1 MJ | 239006 cal | |
| 5 MJ | 1.19503e+06 cal | |
| 10 MJ | 2.39006e+06 cal | |
| 50 MJ | 1.19503e+07 cal | |
| 100 MJ | 2.39006e+07 cal | |
| 1000 MJ | 2.39006e+08 cal |
Formula: Calorie = Megajoule × 239,000
Multiply any megajoule value by 239,000 to get calorie.
Reverse: Megajoule = Calorie × 4.1840e-6
Common megajoule values — factor: 1 MJ = 239,000 cal
| Megajoule (MJ) | Calorie (cal) | Context |
|---|---|---|
| 0.001 MJ | 239 cal | 1 kJ |
| 0.01 MJ | 2,390 cal | 10 kJ |
| 0.1 MJ | 2.39e+04 cal | 100 kJ |
| 1 MJ | 2.39e+05 cal | 1 MJ |
| 3.6 MJ | 8.604e+05 cal | 1 kWh |
| 10 MJ | 2.39e+06 cal | 10 kWh |
| 34 MJ | 8.126e+06 cal | 1L petrol |
| 100 MJ | 2.39e+07 cal | ~28 kWh |
| 360 MJ | 8.604e+07 cal | 100 kWh |
| 1,000 MJ | 2.39e+08 cal | ~278 kWh |
| 4,600 MJ | 1.099e+09 cal | 1 tonne TNT |
| 1e+04 MJ | 2.390e+09 cal | ~2.8 MWh |
| 1e+05 MJ | 2.390e+10 cal | ~28 MWh |
| 1e+06 MJ | 2.390e+11 cal | ~278 MWh |
| 1.000e+09 MJ | 2.390e+14 cal | ~278 GWh |
1 MJ = 239,000 cal. Memorize for instant estimates.
Use 239,000 as a quick mental multiplier.
Multiply result by 4.1840e-6 to recover the original MJ value.
Measures fuel energy content — 1 liter of petrol ≈ 34 MJ.
Compares battery pack energy in MJ and kWh for range calculations.
Quantifies explosive yield — 1 kg TNT ≈ 4.6 MJ.
Calculates daily/annual energy yield of solar and wind in MJ.
Compares fuel energy costs across transport modes in MJ/km.
Models annual heating and cooling energy demand in MJ.
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.
The calorie (cal) was defined in 1824 as the heat needed to raise 1 gram of water by 1°C. There are two versions: the small calorie (cal = 4.184 J) and the large calorie or kilocalorie (kcal = 4,184 J), which is the 'Calorie' used in nutrition.
The calorie remains standard in chemistry for heat of reaction measurements. In the US, food packaging uses 'Calories' (with capital C) which are actually kilocalories — a persistent source of confusion.
Interesting fact: The confusion between cal and kcal means that a food label saying '200 Calories' actually means 200 kcal = 200,000 cal = 836,800 joules. The SI unit for food energy is the kilojoule.
Converting megajoule to calorie 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 MJ = 1.195e+06 cal and 10 MJ = 2.39e+06 cal. Reverse: 1 cal = 4.1840e-6 MJ. Exact factor: 1 MJ = 239,000 cal.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.