Watt-Hour to Megajoule Converter

Energy Converter

27 units available

Decimals:

From

To

0.0036

1 Wh = 0.0036 MJ

Formula:

MJ = Wh × 0.0036

With your value: 1 Wh = 0.0036 MJ

How big is that?

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

Heartbeat (1/3.6e+3 your value)0.000278 Wh

Your value1.00 Wh

AA battery charge (2.8× your value)2.78 Wh

Slice of bread (78× your value)77.8 Wh

Daily food intake (2.3e+3× your value)2.33e+3 Wh

Litre of petrol (9.5e+3× your value)9.50e+3 Wh

Other Watt-Hour to Megajoule conversions

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

Watt-Hour to Megajoule Conversion Table

Watt-Hour (Wh)	Megajoule (MJ)
0.5	0.0018
1	0.0036
2	0.0072
5	0.018
10	0.036
15	0.054
20	0.072
25	0.09
50	0.18
100	0.36
250	0.9
500	1.8
1000	3.6

Megajoule to Watt-Hour Conversion Table

Megajoule (MJ)	Watt-Hour (Wh)
0.5	138.888889
1	277.777778
2	555.555556
5	1,388.888889
10	2,777.777778
15	4,166.666667
20	5,555.555556
25	6,944.444444
50	13,888.888889
100	27,777.777778
250	69,444.444444
500	138,888.888889
1000	277,777.777778

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.

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

Megajoule (MJ)

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 Watt-Hour to Megajoule

To convert from Watt-Hour (Wh) to Megajoule (MJ), multiply the value by 0.0036.

Formula: MJ = Wh × 0.0036

Reverse: Wh = MJ × 277.7777777778

Step-by-Step Example

Start with your value in Watt-Hour. For example: 5 Wh
Multiply by the conversion factor: 5 x 0.0036
The result is: 0.018 MJ

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.

About Megajoule

The megajoule (MJ) is a unit of energy and work. One megajoule equals 1.000000 × 10^+6 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 Megajoule are in 1 Watt-Hour?

There are exactly 0.0036 Megajoule in 1 Watt-Hour. This means the conversion factor from Watt-Hour to Megajoule is 0.0036.

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

The formula to convert Watt-Hour to Megajoule is: MJ = Wh × 0.0036. For example, to convert 10 Watt-Hour to Megajoule, you would multiply 10 by 0.0036.

What is a Watt-Hour?