Convert megajoules to kilowatt-hours

1 MJ=0.2778kWh

Use the converter below to change any megajoules value into kilowatt-hours instantly — with formula, conversion table, and real-world examples.

You have

Equals

0.27778

Conversion formula

Forward

kilowatt-hours = megajoules × 0.2778

Reverse

megajoules = kilowatt-hours × 3.6

Example: 10 MJ × 0.2778 = 2.77778 kWh.

About both units

From

Megajoule

The megajoule equals 1,000,000 joules. Used for fuel energy content, large-scale mechanical work and in some European natural-gas billing. A litre of petrol contains about 34 MJ of energy.

Real-world: 1 L petrol: ~34 MJ. 1 L diesel: ~38 MJ. Tesla Model 3 full charge: ~270 MJ.

Read full megajoule reference →

Kilowatt-Hour

kWh

The kilowatt-hour equals 3.6 megajoules — energy delivered by 1 kW for 1 hour. It is the standard unit on electricity bills worldwide. A UK home uses about 2900 kWh/year; an EV charge adds 10–80 kWh depending on battery.

Real-world: UK home: ~2900 kWh/year. Tesla Model 3 battery: 60–80 kWh. Typical EV efficiency: 15–20 kWh/100 km.

Read full kilowatt-hour reference →

Megajoule to Kilowatt-Hour conversion table

Common megajoules to kilowatt-hours values for quick reference.

Megajoule (MJ)	Kilowatt-Hour (kWh)
1 MJ	0.2778 kWh
10 MJ	2.77778 kWh
100 MJ	27.7778 kWh
500 MJ	138.889 kWh
1,000 MJ	277.778 kWh
5,000 MJ	1,388.89 kWh
10,000 MJ	2,777.78 kWh
50,000 MJ	13,888.89 kWh
100,000 MJ	27,777.78 kWh
500,000 MJ	138,888.89 kWh

Tips & common mistakes

Quick tips

1 MJ = 1000 kJ = 0.278 kWh.
Natural gas heat content often quoted as MJ/m³.
For fuel economy, use MJ/km or L/100km interchangeably.

Avoid these

Confusing MJ with MW (power).
Using MJ for electricity bills — kWh is standard.
Mixing fuel energy (MJ) with fuel volume (L) without unit conversion.

Frequently asked questions

How many kilowatt-hours in a megajoule?

One megajoule equals 0.2778 kilowatt-hours.

How do I convert megajoules to kilowatt-hours?

Multiply the megajoule value by 0.2778 to get the equivalent in kilowatt-hours.

What is 100 megajoules in kilowatt-hours?

100 megajoules equals 27.7778 kilowatt-hours.

Is a megajoule bigger than a kilowatt-hour?

No. 1 megajoule equals 0.2778 kilowatt-hours, so one megajoule is smaller.

How to convert megajoules to kilowatt-hours without a calculator?

Multiply by 0.28 for a quick estimate; use a calculator for precise results.

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