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Convert Watt-hours to Kilojoules

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Science

Energy Converter
10 sig. figures
Formula1 Wh ร— 3.6 = 3.6 kJ
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About Energy Conversions

One quantity, energy, shows up under a different unit in every field. The joule is the SI base; from there it ties to the food calorie in nutrition (1 Calorie = 4,184 joules), the kilowatt-hour on your power bill, the British thermal unit in HVAC, and the electron volt in particle physics. Numbers make the scale concrete: a 2,000-calorie day is about 8.4 megajoules, and a household burning 900 kWh a month runs through roughly 3.24 gigajoules. Every unit below converts on exact factors.

Quick Conversions

Watt-hoursKilojoules
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
Unit NameSymbolPer 1 Watt-hour
British Thermal UnitBTU3.41214
Caloriecal860.421
Electron VolteV2.24694 ร— 10ยฒยฒ
JouleJ3600
Kilocaloriekcal0.860421
KilojoulekJ3.6
Kilowatt-hourkWh0.001
MegajouleMJ0.0036
Watt-hourWh1

Frequently Asked Questions

How do I convert Watt-hours to Kilojoules?

To convert Watt-hours to Kilojoules, use the conversion where 1 Watt-hour (Wh) = 3.6 Kilojoules (kJ). For example, 1 Watt-hour = 3.6 Kilojoules.

What are common Watt-hour to Kilojoule conversions?

Here are common conversions: 1 Watt-hours = 3.6 Kilojoules, 5 Watt-hours = 18 Kilojoules, 10 Watt-hours = 36 Kilojoules, 25 Watt-hours = 90 Kilojoules, 50 Watt-hours = 180 Kilojoules, 100 Watt-hours = 360 Kilojoules.

When would I need to convert Watt-hours to Kilojoules?

Energy conversions are needed when comparing electricity bills across regions using different units, in engineering calculations involving mechanical and thermal energy, for understanding nutritional energy (calories vs joules), and in renewable energy system planning.

How precise are the conversions?

All conversions use exact factors verified against NIST and ISO standards with up to 10 significant figures of precision. Results are calculated using IEEE 754 double-precision arithmetic, which provides approximately 15-17 significant digits. For temperature and other non-linear conversions, exact formulas are used rather than approximations.

Sources

Read our full methodology โ†’