Convert kilojoules to kilowatt-hours

1 kJ=0.0002778kWh

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

You have

Equals

0.00027778

Conversion formula

Forward

kilowatt-hours = kilojoules × 0.0002778

Reverse

kilojoules = kilowatt-hours × 3,600

Example: 10 kJ × 0.0002778 = 0.002778 kWh.

About both units

From

Kilojoule

The kilojoule equals 1000 joules. Used on European nutrition labels (required by EU law alongside kcal), for mechanical work specifications, and some engineering contexts. A 100 g chocolate bar contains about 2100 kJ.

Real-world: 100 g chocolate: ~2100 kJ. EU daily intake (adult): ~8400 kJ. Tesla Model 3 battery: ~270 MJ = 270,000 kJ.

Read full kilojoule 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 →

Kilojoule to Kilowatt-Hour conversion table

Common kilojoules to kilowatt-hours values for quick reference.

Kilojoule (kJ)	Kilowatt-Hour (kWh)
1 kJ	0.0002778 kWh
10 kJ	0.002778 kWh
100 kJ	0.02778 kWh
500 kJ	0.1389 kWh
1,000 kJ	0.2778 kWh
5,000 kJ	1.38889 kWh
10,000 kJ	2.77778 kWh
50,000 kJ	13.8889 kWh
100,000 kJ	27.7778 kWh
500,000 kJ	138.889 kWh

Tips & common mistakes

Quick tips

1 kJ = 1000 J = 0.239 kcal.
EU nutrition labels must show both kJ and kcal.
For quick conversion: kcal × 4.2 = kJ.

Avoid these

Assuming European labels use kcal only — they use both kJ and kcal.
Confusing kJ with kW (power).
Using kcal when kJ is requested in scientific context.

Frequently asked questions

How many kilowatt-hours in a kilojoule?

One kilojoule equals 0.0002778 kilowatt-hours.

How do I convert kilojoules to kilowatt-hours?

Multiply the kilojoule value by 0.0002778 to get the equivalent in kilowatt-hours.

What is 100 kilojoules in kilowatt-hours?

100 kilojoules equals 0.02778 kilowatt-hours.

Is a kilojoule bigger than a kilowatt-hour?

No. 1 kilojoule equals 0.0002778 kilowatt-hours, so one kilojoule is smaller.

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

Multiply by 0 for a quick estimate; use a calculator for precise results.

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