Megajoule to Kilowatt-hour Converter
Enter the value that you want to convert megajoule (MJ) to kilowatt-hour (kW/h) or kilowatt-hour to megajoule.Also written as MJ to KW/H conversion.
1 megajoule = 0.2777778 kilowatt-hour
Formula: kilowatt-hour = megajoule value × 0.2777778
MJ to KW/H — megajoule to kilowatt-hour
10 megajoule = 2.77778 kilowatt-hour
Popular Energy Converters:
Megajoule vs Kilowatt-hour
What is Megajoule?
Megajoule (MJ) is a unit of energy measurement. 1 megajoule is equal to 0.2777778 kilowatt-hour.
What is Kilowatt-hour?
Kilowatt-hour (kW/h) is a unit of energy measurement. 1 kilowatt-hour is equal to 3.6000000 megajoule.
Energy Units in Different Fields
Energy measurement units reflect their historical origins across different industries. Electrical engineers use kilowatt-hours, nutritionists use calories, physicists use joules, heating engineers use BTUs, and the petroleum industry uses barrels of oil equivalent. Converting between these units is essential for energy auditing, comparing fuel sources, sizing HVAC systems, and understanding electricity bills relative to gas consumption.
megajoule to kilowatt-hour metric conversion table
| 0.01 MJ | = | 0.00278 kW/h |
| 0.1 MJ | = | 0.02778 kW/h |
| 1 MJ | = | 0.27778 kW/h |
| 2 MJ | = | 0.55556 kW/h |
| 3 MJ | = | 0.83333 kW/h |
| 4 MJ | = | 1.11111 kW/h |
| 5 MJ | = | 1.38889 kW/h |
| 6 MJ | = | 1.66667 kW/h |
| 7 MJ | = | 1.94444 kW/h |
| 8 MJ | = | 2.22222 kW/h |
| 9 MJ | = | 2.50000 kW/h |
| 10 MJ | = | 2.77778 kW/h |
| 11 MJ | = | 3.05556 kW/h |
| 12 MJ | = | 3.33333 kW/h |
| 13 MJ | = | 3.61111 kW/h |
| 14 MJ | = | 3.88889 kW/h |
| 15 MJ | = | 4.16667 kW/h |
| 16 MJ | = | 4.44444 kW/h |
| 17 MJ | = | 4.72222 kW/h |
| 18 MJ | = | 5.00000 kW/h |
| 19 MJ | = | 5.27778 kW/h |
| 20 MJ | = | 5.55556 kW/h |
| 30 MJ | = | 8.33333 kW/h |
| 40 MJ | = | 11.11111 kW/h |
| 50 MJ | = | 13.88889 kW/h |
| 60 MJ | = | 16.66667 kW/h |
| 70 MJ | = | 19.44444 kW/h |
| 80 MJ | = | 22.22222 kW/h |
| 90 MJ | = | 25.00000 kW/h |
| 100 MJ | = | 27.77778 kW/h |
| 200 MJ | = | 55.55556 kW/h |
| 300 MJ | = | 83.33333 kW/h |
| 400 MJ | = | 111.11111 kW/h |
| 500 MJ | = | 138.88889 kW/h |
| 600 MJ | = | 166.66667 kW/h |
| 700 MJ | = | 194.44444 kW/h |
| 800 MJ | = | 222.22222 kW/h |
| 900 MJ | = | 250.00000 kW/h |
| 1000 MJ | = | 277.77778 kW/h |
How to Convert MJ to KW/H (Megajoule to Kilowatt-hour)?
We can convert megajoule to kilowatt-hour by using an example.
Example:
Convert 20 Megajoule to Kilowatt-hour?
We know 1 Megajoule = 0.2777778 kilowatt-hour; 1 Kilowatt-hour = 3.6000000 megajoule.
20 megajoule = ___kW/h
20 × 0.2777778 = 5.55556 kW/h (we know 1 megajoule = 0.2777778 kilowatt-hour)
Answer:
20 megajoule = 5.55556 kilowatt-hour
How to Convert Megajoules to Kilowatt-Hours (Step-by-Step)
Converting MJ to kWh bridges SI energy measurements with practical electricity units. The conversion factor is 1 MJ = 0.277778 kWh (or equivalently, 3.6 MJ = 1 kWh). This is essential for comparing fuel energy with electrical energy generation or consumption.
- Identify the energy value in megajoules.
- Divide by 3.6 to convert to kilowatt-hours (or multiply by 0.277778).
- This works because 1 kWh = 3.6 MJ exactly.
- Round based on the precision of your original measurement.
Common MJ to kWh Conversions
Reference values for converting fuel and industrial energy (MJ) to electricity-equivalent units (kWh).
| Megajoule | Kilowatt-hour |
|---|---|
| 1 MJ | 0.278 kWh |
| 3.6 MJ | 1 kWh |
| 10 MJ | 2.78 kWh |
| 36 MJ | 10 kWh |
| 120 MJ | 33.3 kWh |
| 1,000 MJ (1 GJ) | 277.8 kWh |
| 3,600 MJ | 1,000 kWh (1 MWh) |
Solved Examples: MJ to kWh
Question 1: Natural gas has 38.3 MJ per cubic meter. How many kWh is that?
Solution:
Start with 38.3 MJ/m³.
Divide by 3.6: 38.3 ÷ 3.6 = 10.64 kWh/m³.
Answer: 38.3 MJ/m³ = 10.64 kWh/m³ of natural gas
Question 2: A solar thermal collector absorbs 25 MJ during a sunny day. Express in kWh.
Solution:
Start with 25 MJ.
Divide by 3.6: 25 ÷ 3.6 = 6.94 kWh.
Answer: 25 MJ = 6.94 kWh of thermal energy
Question 3: Gasoline contains about 34 MJ per liter. What is the kWh equivalent?
Solution:
Start with 34 MJ/liter.
Divide by 3.6: 34 ÷ 3.6 = 9.44 kWh/liter.
A 50-liter tank = 50 × 9.44 = 472 kWh of chemical energy.
Answer: 34 MJ/L = 9.44 kWh/L (a full 50L tank holds 472 kWh)
Question 4: A factory uses 5,400 MJ of energy daily. Express in kWh.
Solution:
Start with 5,400 MJ.
Divide by 3.6: 5,400 ÷ 3.6 = 1,500 kWh.
Answer: 5,400 MJ = 1,500 kWh = 1.5 MWh daily
Practice: MJ to kWh
Try solving these on your own to test your understanding:
- Convert 7.2 MJ to kWh. (Answer: 2.0 kWh)
- Diesel has 38.6 MJ/L. Express in kWh/L. (Answer: 10.72 kWh/L)
- Convert 500 MJ to kWh. (Answer: 138.9 kWh)
- A battery stores 18 MJ. How many kWh is that? (Answer: 5.0 kWh)
- Convert 90 MJ to kWh. (Answer: 25.0 kWh)
Fuel vs Electricity: Energy Comparison in kWh
Converting fuel energy (MJ) to kWh enables direct comparison with electricity. One gallon of gasoline (120 MJ = 33.3 kWh) contains more energy than a typical EV battery charge (60 kWh for a mid-range EV). However, internal combustion engines are only 20–30% efficient, while electric motors are 85–95% efficient. So that 33.3 kWh in gasoline delivers only ~8.3 kWh to the wheels, while 33.3 kWh of electricity delivers ~30 kWh to an EV's wheels.
National Energy Statistics: MJ to kWh in Policy
Government energy reports often present consumption in MJ, GJ, or TJ (terajoules). Converting to kWh makes these figures more relatable. For example, if a country reports per-capita energy use of 180 GJ/year, that equals 180,000 MJ ÷ 3.6 = 50,000 kWh/year or about 137 kWh/day per person — covering electricity, transport, heating, and industry combined.
Power Plant Efficiency in MJ and kWh
A coal power plant burns coal with ~24 MJ/kg energy content but converts only 33–40% to electricity. So 1 kg of coal (24 MJ = 6.67 kWh thermal) produces about 2.2–2.7 kWh of electricity. Modern combined-cycle gas plants achieve 55–62% efficiency: 1 m³ of natural gas (38 MJ = 10.6 kWh thermal) yields 5.8–6.5 kWh electricity. These conversions are fundamental to energy policy analysis.
Key Takeaways
- Divide MJ by 3.6 to get kWh (or multiply by 0.277778).
- 3.6 MJ = 1 kWh exactly — the key equivalence to remember.
- Gasoline: 34 MJ/L = 9.4 kWh/L; a gallon ≈ 33.3 kWh of chemical energy.
- This conversion enables apples-to-apples fuel vs electricity comparisons.
- Consider efficiency: engines use only 20–30% of fuel energy; EVs use 85–95%.
- 1 GJ = 277.8 kWh; 1 TJ = 277,778 kWh — useful for national statistics.
Megajoule to Kilowatt-hour Conversion Formula
kilowatt-hour = megajoule × 0.2777778
1 megajoule = 0.2777778 kilowatt-hour
1 kilowatt-hour = 3.6000000 megajoule
Reverse: megajoule = kilowatt-hour × 3.6000000
Frequently Asked Questions
How many kilowatt-hour are in 1 megajoule?
There are 0.2777778 kilowatt-hour in 1 megajoule. To convert megajoule to kilowatt-hour, multiply the value by 0.2777778.
How do I convert megajoule to kilowatt-hour?
Multiply your megajoule value by 0.2777778 to get the equivalent in kilowatt-hour. For example, 5 megajoule = 5 × 0.2777778 = 1.38889 kilowatt-hour.
How do I convert kilowatt-hour to megajoule?
Multiply your kilowatt-hour value by 3.6000000 to get the equivalent in megajoule. Alternatively, divide by 0.2777778.
What is 10 megajoule in kilowatt-hour?
10 megajoule is equal to 2.77778 kilowatt-hour.
What is 100 megajoule in kilowatt-hour?
100 megajoule is equal to 27.77778 kilowatt-hour.