Kilojoules to Kilowatt Hours Converter

Kilojoules to Kilowatt Hours

Convert kilojoules (kJ) to kilowatt hours (kWh). Both measure work and power, and the conversion comes up in nutrition, electricity, fitness work.

The Formula

`` kilowatt hours = kilojoules × 0.000277777777778 kilojoules = kilowatt hours × 3600 `

One kilojoule is 2.7778e-4 kilowatt hours, and one kilowatt hour is 3,600 kilojoules.

Conversion Table

Kilojoules	Kilowatt Hours
1 kJ	2.7778e-4 kWh
2 kJ	5.5556e-4 kWh
5 kJ	0.001389 kWh
10 kJ	0.002778 kWh
25 kJ	0.006944 kWh
50 kJ	0.013889 kWh
100 kJ	0.027778 kWh
500 kJ	0.138889 kWh
1,000 kJ	0.277778 kWh

The Other Direction

Kilowatt Hours	Kilojoules
1 kWh	3,600 kJ
2 kWh	7,200 kJ
5 kWh	18,000 kJ
10 kWh	36,000 kJ
25 kWh	90,000 kJ
50 kWh	180,000 kJ
100 kWh	360,000 kJ
500 kWh	1,800,000 kJ
1,000 kWh	3,600,000 kJ

What Each Unit Is

Kilojoules (kJ) — 1,000 joules. The metric food-energy unit outside North America.

Kilowatt Hours (kWh) — 1,000 watt-hours, or 3.6 million joules. The unit electricity has been billed in since metering began.

A Sense of Scale

• An apple holds about 400 kJ
• Daily intake is around 8,700 kJ
• A home uses 8–30 kWh a day
• An EV takes 15–20 kWh per 100 km

Precision

The factor 0.000277777777778 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.

In Code

`javascript const kilojouleToKilowattHour = (value) => value * 0.000277777777778; ``

Where This Conversion Comes Up

• Nutrition
• Electricity
• Fitness
• Heating
• Fuel

How Many Decimals Do You Need?

Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 kJ with the factor truncated at each decimal place:

Decimals kept	Factor	137 kJ becomes	Error
0	0	0	100.0000%
1	0	0	100.0000%
2	0	0	100.0000%
3	0	0	100.0000%
4	0.0003	0.0411	8.0000%

A rule that holds for any conversion: round once, at the end. Rounding the factor and then multiplying compounds the error through every subsequent calculation, while carrying full precision and rounding the final answer does not.

The right number of significant figures is set by your input, not by the converter. If you measured kilojoules to three significant figures, the answer in kilowatt hours is only good to three — writing more digits claims precision the measurement never had.

Other Conversions From Kilojoules

The same value in every other unit this converter supports for energy:

From	To	Unit
1 kJ	1,000 J	Joules
1 kJ	239.006 cal	Calories
1 kJ	0.239006 kcal	Kilocalories
1 kJ	0.277778 Wh	Watt Hours
1 kJ	0.947817 BTU	BTU

Chaining conversions works — kilojoules to metres to feet gives the same answer as kilojoules to feet — but each step rounds, so a chain of three conversions carries three roundings. Convert directly where a direct factor exists.