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Convert Watt-hours to Joules

One watt-hour equals 3,600 joules. Type any value to convert watt-hours to joules instantly — with a full reference table below.

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Convert Watt-hours to Joules

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Formula

How to convert Watt-hours to Joules

To convert watt-hours to joules, multiply by 3,600. One watt-hour equals 3,600 J, and one joule equals 0.000277778 Wh.

  1. Take the value in watt-hours — for example 7.5 Wh.
  2. Multiply by 3,600 (the number of joules in one watt-hour).
  3. 7.5 × 3,600 = 27,000 J.

Watt-hours to Joules conversion table

Watt-hoursJoules
1 Wh3,600 J
2 Wh7,200 J
5 Wh18,000 J
10 Wh36,000 J
20 Wh72,000 J
50 Wh180,000 J
100 Wh360,000 J
200 Wh720,000 J
500 Wh1,800,000 J
1,000 Wh3,600,000 J
2,000 Wh7,200,000 J
JoulesWatt-hours
1 J0.000277778 Wh
2 J0.000555556 Wh
5 J0.00138889 Wh
10 J0.00277778 Wh
20 J0.00555556 Wh
50 J0.0138889 Wh
100 J0.0277778 Wh
200 J0.0555556 Wh
500 J0.138889 Wh
1,000 J0.277778 Wh
2,000 J0.555556 Wh

About converting Watt-hours to Joules

Watt-hours (Wh) and Joules (J) are both units of energy. The exact factor is 1 Wh = 3,600 J, so multiply by 3,600 to go from watt-hours to joules (or divide to go back).

The conversion runs entirely in your browser. Need the reverse? Use the Joules to Watt-hours converter, or the full unit converter for every unit at once.

Real-world energy in watt-hours and joules

ExampleWatt-hoursJoules
One food Calorie (kcal)1.162222 Wh4,184 J
A 100 W bulb running for one hour100 Wh360,000 J
A smartphone battery (≈19 Wh)≈ 19.25 Wh≈ 69,300 J

“≈” marks typical values; the rest are defined or measured figures.

The units

Watt-hours (Wh)

One watt for one hour: exactly 3,600 J.

Used for: Battery capacity (power banks, laptops).

Joules (J)

The SI unit of energy: the work done by one newton over one metre.

Used for: Science and food labels (kJ).

The thermochemical calorie is exactly 4.184 J and a kilowatt-hour is exactly 3.6 MJ, so these factors are exact.

Frequently asked questions

5 answers
How many joules are in one watt-hour?
One watt-hour equals 3,600 joules.
How do I convert watt-hours to joules?
Multiply the number of watt-hours by 3,600. For example, 10 watt-hours = 36,000 joules.
What is 5 watt-hours in joules?
5 watt-hours is 18,000 joules.
Is a watt-hour bigger than a joule?
Yes. One watt-hour equals 3,600 joules, so it is 3,600 times larger.
How many joules is a 100 W bulb running for one hour?
A 100 W bulb running for one hour is 360,000 joules (100 watt-hours).