Kilojoule to Watt-Hour Converter

Energy Converter

27 units available

Decimals:

From

To

0.277778

1 kJ = 0.277778 Wh

Formula:

Wh = kJ × 0.2777777778

With your value: 1 kJ = 0.27777778 Wh

How big is that?

Everyday references on a logarithmic scale, all expressed in kilojoule so you can sanity-check the result.

Heartbeat (1/1.0e+3 your value)0.00100 kJ

Your value1.00 kJ

AA battery charge (10× your value)10.0 kJ

Slice of bread (2.8e+2× your value)280 kJ

Daily food intake (8.4e+3× your value)8.40e+3 kJ

Litre of petrol (3.4e+4× your value)3.42e+4 kJ

Other Kilojoule to Watt-Hour conversions

2 kJ to Wh 3 kJ to Wh 4 kJ to Wh 5 kJ to Wh 6 kJ to Wh 7 kJ to Wh 8 kJ to Wh

Kilojoule to Watt-Hour Conversion Table

Kilojoule (kJ)	Watt-Hour (Wh)
0.5	0.138889
1	0.277778
2	0.555556
5	1.388889
10	2.777778
15	4.166667
20	5.555556
25	6.944444
50	13.888889
100	27.777778
250	69.444444
500	138.888889
1000	277.777778

Watt-Hour to Kilojoule Conversion Table

Watt-Hour (Wh)	Kilojoule (kJ)
0.5	1.8
1	3.6
2	7.2
5	18
10	36
15	54
20	72
25	90
50	180
100	360
250	900
500	1,800
1000	3,600

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Kilojoule (kJ)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Watt-Hour (Wh)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Kilojoule to Watt-Hour

To convert from Kilojoule (kJ) to Watt-Hour (Wh), multiply the value by 0.2777777778.

Formula: Wh = kJ × 0.2777777778

Reverse: kJ = Wh × 3.6

Step-by-Step Example

Start with your value in Kilojoule. For example: 5 kJ
Multiply by the conversion factor: 5 x 0.2777777778
The result is: 1.388889 Wh

About Kilojoule

The kilojoule (kJ) is a unit of energy and work. One kilojoule equals 1000 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

About Watt-Hour

The watt-hour (Wh) is a unit of energy and work. One watt-hour equals 3600 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

Frequently Asked Questions

How many Watt-Hour are in 1 Kilojoule?

There are exactly 0.2777777778 Watt-Hour in 1 Kilojoule. This means the conversion factor from Kilojoule to Watt-Hour is 0.2777777778.

What is the formula to convert Kilojoule to Watt-Hour?

The formula to convert Kilojoule to Watt-Hour is: Wh = kJ × 0.2777777778. For example, to convert 10 Kilojoule to Watt-Hour, you would multiply 10 by 0.2777777778.

What is a Kilojoule?