CalcPairsKilowatt-Hours to Megajoules Converter (kWh to MJ)
10 kWh is 36 megajoules. A kilowatt-hour is a kilowatt sustained for an hour — 1,000 watts × 3,600 seconds = 3,600,000 joules = exactly 3.6 MJ. So kWh × 3.6 gives MJ, with nothing approximate anywhere in it.
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How this conversion works
Electricity is billed in kWh, batteries are sold in kWh, but physics and engineering speak joules. Type either side: an EV battery of 60 kWh holds 216 MJ; a 100 MJ quantity of energy is 27.78 kWh — about a day of electricity for a typical US home.
The megajoule makes a good reality check across fuels: a litre of petrol carries about 34 MJ, roughly 9.4 kWh — which is why a modest fuel tank holds the energy of a very large battery, and why the conversion on this page keeps appearing in energy debates.
The exact formula
megajoules = kilowatt-hours × 3.6
1 kWh = 1 kW × 3,600 s = 3.6 × 10⁶ J = 3.6 MJ, exactly. The reverse is kilowatt-hours = megajoules ÷ 3.6.
Kilowatt-hours to Megajoules conversion table
| Kilowatt-hours (kWh) | Megajoules (MJ) |
|---|---|
| 1 | 3.6 |
| 2 | 7.2 |
| 3 | 10.8 |
| 4 | 14.4 |
| 5 | 18 |
| 6 | 21.6 |
| 7 | 25.2 |
| 8 | 28.8 |
| 9 | 32.4 |
| 10 | 36 |
| Kilowatt-hours (kWh) | Megajoules (MJ) |
|---|---|
| 11 | 39.6 |
| 12 | 43.2 |
| 13 | 46.8 |
| 14 | 50.4 |
| 15 | 54 |
| 16 | 57.6 |
| 17 | 61.2 |
| 18 | 64.8 |
| 19 | 68.4 |
| 20 | 72 |
| Kilowatt-hours (kWh) | Megajoules (MJ) |
|---|---|
| 21 | 75.6 |
| 22 | 79.2 |
| 23 | 82.8 |
| 24 | 86.4 |
| 25 | 90 |
| 26 | 93.6 |
| 27 | 97.2 |
| 28 | 100.8 |
| 29 | 104.4 |
| 30 | 108 |
| Kilowatt-hours (kWh) | Megajoules (MJ) |
|---|---|
| 31 | 111.6 |
| 32 | 115.2 |
| 33 | 118.8 |
| 34 | 122.4 |
| 35 | 126 |
| 36 | 129.6 |
| 37 | 133.2 |
| 38 | 136.8 |
| 39 | 140.4 |
| 40 | 144 |
| Kilowatt-hours (kWh) | Megajoules (MJ) |
|---|---|
| 41 | 147.6 |
| 42 | 151.2 |
| 43 | 154.8 |
| 44 | 158.4 |
| 45 | 162 |
| 46 | 165.6 |
| 47 | 169.2 |
| 48 | 172.8 |
| 49 | 176.4 |
| 50 | 180 |
| Kilowatt-hours (kWh) | Megajoules (MJ) |
|---|---|
| 75 | 270 |
| 100 | 360 |
| 250 | 900 |
| 500 | 1800 |
| 1000 | 3600 |
Frequently asked questions
How many MJ are in 1 kWh?
Exactly 3.6 MJ.
How many kWh is 100 MJ?
27.777778 kWh.
Is a kWh a unit of power or energy?
Energy. It is power (kilowatts) multiplied by time (hours) — the amount a 1 kW heater uses in one hour, or a 2 kW heater in half an hour.