Megajoules to Watt-Hours Conversion (MJ to Wh)

Megajoules to Watt-Hours Converter

Enter the energy in megajoules below to convert it to watt-hours.

Result in Watt-Hours:

1 MJ = 277.777778 Wh

How to Convert Megajoules to Watt-Hours

To convert a measurement in megajoules to a measurement in watt-hours, multiply the energy by the following conversion ratio: 277.777778 watt-hours/megajoule.

Since one megajoule is equal to 277.777778 watt-hours, you can use this simple formula to convert:

watt-hours = megajoules × 277.777778

The energy in watt-hours is equal to the energy in megajoules multiplied by 277.777778.

For example, here's how to convert 5 megajoules to watt-hours using the formula above.

watt-hours = (5 MJ × 277.777778) = 1,388.888889 Wh

How Many Watt-Hours Are in a Megajoule?

There are 277.777778 watt-hours in a megajoule, which is why we use this value in the formula above.

1 MJ = 277.777778 Wh

Megajoules and watt-hours are both units used to measure energy. Keep reading to learn more about each unit of measure.

What Is a Megajoule?

One megajoule is equal to 1,000,000 joules, which is the energy equal to the force on an object of one newton at a distance of one meter.

The megajoule is a multiple of the joule, which is the SI derived unit for energy. In the metric system, "mega" is the prefix for millions, or 10⁶. Megajoules can be abbreviated as MJ; for example, 1 megajoule can be written as 1 MJ.

Learn more about megajoules.

What Is a Watt-Hour?

The watt-hour is a measure of electrical energy equal to one watt of power over a one hour period.

Watt-hours are usually abbreviated as Wh, although the formally adopted expression is W·h. The abbreviation W h is also sometimes used. For example, 1 watt-hour can be written as 1 Wh, 1 W·h, or 1 W h.

In formal expressions, the centered dot (·) or space is used to separate units used to indicate multiplication in an expression and to avoid conflicting prefixes being misinterpreted as a unit symbol.^[1]

Learn more about watt-hours.

Megajoule to Watt-Hour Conversion Table

Table showing various megajoule measurements converted to watt-hours.
Megajoules	Watt-hours
1 MJ	277.78 Wh
2 MJ	555.56 Wh
3 MJ	833.33 Wh
4 MJ	1,111 Wh
5 MJ	1,389 Wh
6 MJ	1,667 Wh
7 MJ	1,944 Wh
8 MJ	2,222 Wh
9 MJ	2,500 Wh
10 MJ	2,778 Wh
11 MJ	3,056 Wh
12 MJ	3,333 Wh
13 MJ	3,611 Wh
14 MJ	3,889 Wh
15 MJ	4,167 Wh
16 MJ	4,444 Wh
17 MJ	4,722 Wh
18 MJ	5,000 Wh
19 MJ	5,278 Wh
20 MJ	5,556 Wh
21 MJ	5,833 Wh
22 MJ	6,111 Wh
23 MJ	6,389 Wh
24 MJ	6,667 Wh
25 MJ	6,944 Wh
26 MJ	7,222 Wh
27 MJ	7,500 Wh
28 MJ	7,778 Wh
29 MJ	8,056 Wh
30 MJ	8,333 Wh
31 MJ	8,611 Wh
32 MJ	8,889 Wh
33 MJ	9,167 Wh
34 MJ	9,444 Wh
35 MJ	9,722 Wh
36 MJ	10,000 Wh
37 MJ	10,278 Wh
38 MJ	10,556 Wh
39 MJ	10,833 Wh
40 MJ	11,111 Wh

Table showing various megajoule measurements converted to watt-hours.

Megajoules

Watt-hours

1 MJ

277.78 Wh

2 MJ

555.56 Wh

3 MJ

833.33 Wh

4 MJ

1,111 Wh

5 MJ

1,389 Wh

6 MJ

1,667 Wh

7 MJ

1,944 Wh

8 MJ

2,222 Wh

9 MJ

2,500 Wh

10 MJ

2,778 Wh

11 MJ

3,056 Wh

12 MJ

3,333 Wh

13 MJ

3,611 Wh

14 MJ

3,889 Wh

15 MJ

4,167 Wh

16 MJ

4,444 Wh

17 MJ

4,722 Wh

18 MJ

5,000 Wh

19 MJ

5,278 Wh

20 MJ

5,556 Wh

21 MJ

5,833 Wh

22 MJ

6,111 Wh

23 MJ

6,389 Wh

24 MJ

6,667 Wh

25 MJ

6,944 Wh

26 MJ

7,222 Wh

27 MJ

7,500 Wh

28 MJ

7,778 Wh

29 MJ

8,056 Wh

30 MJ

8,333 Wh

31 MJ

8,611 Wh

32 MJ

8,889 Wh

33 MJ

9,167 Wh

34 MJ

9,444 Wh

35 MJ

9,722 Wh

36 MJ

10,000 Wh

37 MJ

10,278 Wh

38 MJ

10,556 Wh

39 MJ

10,833 Wh

40 MJ

11,111 Wh

References

Bureau International des Poids et Mesures, The International System of Units (SI), 9th edition, 2019, https://www.bipm.org/documents/20126/41483022/SI-Brochure-9-EN.pdf