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Joules to Watt-hours Converter

Convert joules (watt-seconds) (J) to watt-hours (Wh), with the formula, a conversion table and exact factors.

Change the values and press Calculate to work out your own figures.

Enter an amount of energy, choose its unit and the unit you want. The answer is exact until it is shown, and the same value appears in every other unit.

A number, fraction (3/8), mixed number (1 1/2), scientific notation (2.5e6) or a simple sum such as 2*3.
The unit you want the answer in. Swap exchanges the two units.
Result
0.000277777777778 Wh
kilojoules
0.001 kJ
megajoules
1 × 10⁻⁶ MJ
gigajoules
1 × 10⁻⁹ GJ
calories (thermochemical)
0.239005736138 cal
kilocalories (food Calories)
0.000239005736138 kcal
megacalories
2.39005736138 × 10⁻⁷ Mcal
kilowatt-hours
2.77777777778 × 10⁻⁷ kWh
megawatt-hours
2.77777777778 × 10⁻¹⁰ MWh
British thermal units (IT)
0.000947817120313 Btu
million Btu
9.47817120313 × 10⁻¹⁰ MMBtu
therms (100,000 Btu)
9.47817120313 × 10⁻⁹ thm
quads (10¹⁵ Btu)
9.47817120313 × 10⁻¹⁹ quad
electronvolts
6.24150907446 × 10¹⁸ eV
kiloelectronvolts
6.24150907446 × 10¹⁵ keV
megaelectronvolts
6,241,509,074,460 MeV

1 J = 0.000277777777778 Wh

Show the working
  1. 1 J = 0.000277777777778 Wh
  2. 1 × 0.000277777777778 = 0.000277777777778 Wh

How to convert joules to watt-hours

1 Wh = 3,600 J, so divide by 3,600 to go from joules (watt-seconds) to watt-hours (1 J = 0.000277777777778 Wh).

Wh = J ÷ 3,600
J = Wh × 3,600

Worked example:

1 J = 0.000277777777778 Wh
5 × 0.000277777777778 = 0.00138888888889 Wh

Joules to watt-hours table

JoulesWatt-hours
1 J0.000277777777778 Wh
2 J0.000555555555556 Wh
3 J0.000833333333333 Wh
4 J0.00111111111111 Wh
5 J0.00138888888889 Wh
6 J0.00166666666667 Wh
7 J0.00194444444444 Wh
8 J0.00222222222222 Wh
9 J0.0025 Wh
10 J0.00277777777778 Wh
15 J0.00416666666667 Wh
20 J0.00555555555556 Wh
25 J0.00694444444444 Wh
30 J0.00833333333333 Wh
40 J0.0111111111111 Wh
50 J0.0138888888889 Wh
75 J0.0208333333333 Wh
100 J0.0277777777778 Wh
250 J0.0694444444444 Wh
500 J0.138888888889 Wh
1000 J0.277777777778 Wh

About the units

Joules (J)
Joules (watt-seconds), a metric unit. Definition: BIPM SI Brochure, 9th edition (SI units, prefixes and units accepted for use with the SI).

Formula version 0.1.0Reviewed