NiftyRecipe Online energy conversion
kWh/BTU 3412.141633 MJ/kJ 1000 MJ/cal 239005.736138 cal/MJ 0.000004 kJ/cal 239.005736 cal/kJ 0.004184
J / Wh

1 joule in watt-hour

0.000278 watt-hour

1 J = 0.000278 Wh · factor

1 joule equals 0.000278 watt-hour. Electrical energy in kilowatt-hours can be expressed as other energy units with fixed physics factors.

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Common values

watt-hour to joule 2 joules in watt-hour 5 joules in watt-hour 10 joules in watt-hour 20 joules in watt-hour 25 joules in watt-hour 50 joules in watt-hour 75 joules in watt-hour 100 joules in watt-hour 120 joules in watt-hour 150 joules in watt-hour

Same amount, other units

1 joule → kcal 1 joule → kJ
Formula: joule to watt-hour

Wh = J × 0.000278 (1 J = 0.000278 WH)

Reference values: joule → watt-hour
J Wh
1 J 0.000278 Wh
100 J 0.027778 Wh
200 J 0.055556 Wh
500 J 0.138889 Wh
1000 J 0.277778 Wh
2000 J 0.555556 Wh

All amounts for this pair

FAQ for J → Wh
1 joule in watt-hour

1 joule equals 0.000278 watt-hour as a pure energy equivalence on NiftyRecipe.

Kilowatt-hours measure delivered electrical energy. Expressing them as kcal, kJ, MJ or BTU is physics only-not a forecast of what a household pays. The factor is 1 joule = 0.000278 watt-hour, so this amount is 0.000278 watt-hour. Reverse: 1 watt-hour ≈ 3600 joule. Note that 1 kWh is exactly 3.6 MJ.

Use the calculator for teaching examples or rough comparisons. For tariffs and bills, use your utility’s tools; for unit math, stay with the constant factor here.