Kilowatt Hours to Kilojoules Converter

Kilowatt Hours to Kilojoules

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

The Formula

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

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

Conversion Table

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

The Other Direction

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

What Each Unit Is

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

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

A Sense of Scale

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

Precision

The factor 3600 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 kilowattHourToKilojoule = (value) => value * 3600; ``

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 kWh with the factor truncated at each decimal place:

Decimals kept	Factor	137 kWh becomes	Error
0	3600	493,200	—
1	3600	493,200	—
2	3600	493,200	—
3	3600	493,200	—
4	3600	493,200	—

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 kilowatt hours to three significant figures, the answer in kilojoules is only good to three — writing more digits claims precision the measurement never had.

Other Conversions From Kilowatt Hours

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

From	To	Unit
1 kWh	3,600,000 J	Joules
1 kWh	860,420.65 cal	Calories
1 kWh	860.421 kcal	Kilocalories
1 kWh	1,000 Wh	Watt Hours
1 kWh	3,412.14 BTU	BTU

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