Marks Calc

watt-hours to kilojoules

Convert watt-hour to kilojoule — instant, free, with the formula shown.

1 Wh=3.6 kJ

How to convert watt-hour to kilojoule

To convert watt-hour to kilojoule, multiply by 3.6:

kJ = Wh × 3.6

For example, 10 Wh × 3.6 = 36 kJ.

Wh to kJ conversion table

watt-hours (Wh)kilojoules (kJ)
1 Wh3.6 kJ
2 Wh7.2 kJ
5 Wh18 kJ
10 Wh36 kJ
25 Wh90 kJ
50 Wh180 kJ
100 Wh360 kJ
250 Wh900 kJ
500 Wh1800 kJ
1000 Wh3600 kJ
Reverse: Kilojoule to Watt-hour

Other watt-hour conversions

Convert to kilojoule from another unit

Wh to kJ — frequently asked

How many kilojoules are in 1 watt-hour?

1 watt-hour = 3.6 kilojoules (Wh × 3.6 = kJ).

What is the formula to convert watt-hour to kilojoule?

Multiply your watt-hour value by 3.6 to get kilojoule.

How do I convert 10 watt-hours to kilojoules?

10 Wh = 36 kJ. For 100 Wh the answer is 360 kJ. Use the calculator on this page for any other value.

When to convert watt-hour to kilojoule

1Electricity bills (kWh)
2Nutrition labels (kcal / food cal)
3HVAC and heating (BTU, therms)
4Physics and chemistry (J, eV)

Energy conversion — common questions

Is a food calorie the same as a calorie?

No — a food 'Calorie' (capital C) actually means 1 kilocalorie = 1,000 small calories = 4,184 J. Nutrition labels typically write 'cal' meaning kcal.

How many joules in 1 kWh?

1 kWh = 3,600,000 J (3.6 MJ). Because 1 kW × 1 hour = 1,000 W × 3,600 s = 3,600,000 J.

What is a BTU?

British Thermal Unit — the energy required to raise 1 pound of water by 1 °F. 1 BTU ≈ 1,055 J.

See all energy converters