Energy

MJ to Wh Converter

Convert megajoules (MJ) to watt-hours (Wh). 1 megajoule = 277.7777778 watt-hours (exact)

1 megajoule = 277.777777778 watt-hours

How to convert megajoules to watt-hours

FormulaWh = MJ × 277.7777778

Because one watt-hour equals 0.0036 megajoules, you can also divide: Wh = MJ ÷ 0.0036.

A megajoule is larger than a watt-hour: one megajoule contains 277.7777778 watt-hours.

Worked examples

  • 1 megajoule1 MJ × 277.7777778 = 277.7777778 Wh
  • 5 megajoules5 MJ × 277.7777778 = 1,388.888889 Wh
  • 10 megajoules10 MJ × 277.7777778 = 2,777.777778 Wh
  • 20 megajoules20 MJ × 277.7777778 = 5,555.555556 Wh
  • 100 megajoules100 MJ × 277.7777778 = 27,777.77778 Wh

Megajoules to watt-hours conversion table

Values are calculated by the conversion engine and rounded to 8 significant figures.

Megajoules to watt-hours: 0.1–10 MJ
Megajoules (MJ)Watt-hours (Wh)
0.1 MJ27.777778 Wh
0.25 MJ69.444444 Wh
0.5 MJ138.88889 Wh
1 MJ277.77778 Wh
2 MJ555.55556 Wh
3 MJ833.33333 Wh
4 MJ1,111.1111 Wh
5 MJ1,388.8889 Wh
6 MJ1,666.6667 Wh
7 MJ1,944.4444 Wh
8 MJ2,222.2222 Wh
9 MJ2,500 Wh
10 MJ2,777.7778 Wh
Megajoules to watt-hours: 12–1,000 MJ
Megajoules (MJ)Watt-hours (Wh)
12 MJ3,333.3333 Wh
15 MJ4,166.6667 Wh
20 MJ5,555.5556 Wh
25 MJ6,944.4444 Wh
30 MJ8,333.3333 Wh
40 MJ11,111.111 Wh
50 MJ13,888.889 Wh
75 MJ20,833.333 Wh
100 MJ27,777.778 Wh
250 MJ69,444.444 Wh
500 MJ138,888.89 Wh
1,000 MJ277,777.78 Wh

About the units

Megajoule (MJ)

The megajoule (MJ) is a unit of energy in the International System of Units (SI). One megajoule equals 1,000,000 joules (J).

Watt-hour (Wh)

One watt sustained for an hour: 3,600 J. Battery capacities are rated in Wh.

Frequently asked questions

How many watt-hours are in one megajoule?

There are 277.7777778 watt-hours in one megajoule, and this value is exact by definition.

How do I convert megajoules to watt-hours?

Multiply the number of megajoules by 277.7777778. For example, 10 MJ × 277.7777778 = 2,777.777778 Wh.

How many megajoules are in one watt-hour?

One watt-hour equals 0.0036 megajoules. That is the reverse factor, 1 ÷ 277.7777778.

What is 10 megajoules in watt-hours?

10 MJ = 2,777.777778 Wh.

Is this MJ to Wh converter accurate?

Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.

Convert megajoules to other units

Convert other units to watt-hours

Try “psi to bar”, “cups”, “binary” or “5 ft in cm”.