Convert Kilowatt-hour to Kilojoule
1 kilowatt-hour = 3,600 kilojoule (kJ). For example, 10 kilowatt-hour = 36,000 kilojoule and 100 kilowatt-hour = 360,000 kilojoule. Type any value below to convert kilowatt-hour to kilojoule both ways — it runs entirely in your browser.
Quick answer: Kilowatt-hour to Kilojoule
1 Kilowatt-hour = 3,600 Kilojoule (kWh → kJ). To convert kilowatt-hour to kilojoule, multiply by 3,600. To convert kilojoule to kilowatt-hour, multiply by 0.0002777778. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common kilowatt-hour-to-kilojoule questions.
How to convert Kilowatt-hour to Kilojoule
To convert kilowatt-hour to kilojoule, multiply the number of kilowatt-hour by the conversion factor 3,600, because 1 kWh = 3,600 kJ. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 kJ = 0.0002777778 kWh, so you divide by 3,600 (or multiply by 0.0002777778) to turn kilojoule back into kilowatt-hour.
kJ = kWh × 3,600 ·
kWh = kJ × 0.0002777778
- Write down the value you want to convert, in kilowatt-hour.
- Multiply it by 3,600.
- The result is the same area/length/quantity expressed in kilojoule.
Kilowatt-hour to Kilojoule — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 kilowatt-hour is 18,000 kilojoule because 5 kWh × 3,600 = 18,000 kJ.
| Kilowatt-hour | Calculation | Kilojoule |
|---|---|---|
| 1 kWh | 1 kWh × 3,600 = 3,600 kJ | 3,600 kJ |
| 2 kWh | 2 kWh × 3,600 = 7,200 kJ | 7,200 kJ |
| 3 kWh | 3 kWh × 3,600 = 10,800 kJ | 10,800 kJ |
| 5 kWh | 5 kWh × 3,600 = 18,000 kJ | 18,000 kJ |
| 7 kWh | 7 kWh × 3,600 = 25,200 kJ | 25,200 kJ |
| 10 kWh | 10 kWh × 3,600 = 36,000 kJ | 36,000 kJ |
| 12 kWh | 12 kWh × 3,600 = 43,200 kJ | 43,200 kJ |
| 15 kWh | 15 kWh × 3,600 = 54,000 kJ | 54,000 kJ |
| 20 kWh | 20 kWh × 3,600 = 72,000 kJ | 72,000 kJ |
| 25 kWh | 25 kWh × 3,600 = 90,000 kJ | 90,000 kJ |
| 50 kWh | 50 kWh × 3,600 = 180,000 kJ | 180,000 kJ |
| 100 kWh | 100 kWh × 3,600 = 360,000 kJ | 360,000 kJ |
Common Kilowatt-hour to Kilojoule conversions
These are the kilowatt-hour-to-kilojoule values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 kilowatt-hour = 3,600 kilojoule
- 2 kilowatt-hour = 7,200 kilojoule
- 2.5 kilowatt-hour = 9,000 kilojoule
- 3 kilowatt-hour = 10,800 kilojoule
- 4 kilowatt-hour = 14,400 kilojoule
- 5 kilowatt-hour = 18,000 kilojoule
- 6 kilowatt-hour = 21,600 kilojoule
- 7 kilowatt-hour = 25,200 kilojoule
- 8 kilowatt-hour = 28,800 kilojoule
- 9 kilowatt-hour = 32,400 kilojoule
- 10 kilowatt-hour = 36,000 kilojoule
- 12 kilowatt-hour = 43,200 kilojoule
- 15 kilowatt-hour = 54,000 kilojoule
- 20 kilowatt-hour = 72,000 kilojoule
- 25 kilowatt-hour = 90,000 kilojoule
- 30 kilowatt-hour = 108,000 kilojoule
- 50 kilowatt-hour = 180,000 kilojoule
- 75 kilowatt-hour = 270,000 kilojoule
- 100 kilowatt-hour = 360,000 kilojoule
- 200 kilowatt-hour = 720,000 kilojoule
- 500 kilowatt-hour = 1,800,000 kilojoule
- 1000 kilowatt-hour = 3,600,000 kilojoule
Kilowatt-hour to Kilojoule conversion chart (both directions)
The chart below converts kilowatt-hour to kilojoule and kilojoule to kilowatt-hour side by side, so it works whichever way you need. 1 kilowatt-hour = 3,600 kilojoule, and 1 kilojoule = 0.0002777778 kilowatt-hour.
| Kilowatt-hour → Kilojoule | Kilojoule → Kilowatt-hour |
|---|---|
| 0.25 kWh = 900 kJ | 0.25 kJ = 0.00006944444 kWh |
| 0.5 kWh = 1,800 kJ | 0.5 kJ = 0.0001388889 kWh |
| 1 kWh = 3,600 kJ | 1 kJ = 0.0002777778 kWh |
| 2 kWh = 7,200 kJ | 2 kJ = 0.0005555556 kWh |
| 3 kWh = 10,800 kJ | 3 kJ = 0.0008333333 kWh |
| 4 kWh = 14,400 kJ | 4 kJ = 0.001111111 kWh |
| 5 kWh = 18,000 kJ | 5 kJ = 0.001388889 kWh |
| 6 kWh = 21,600 kJ | 6 kJ = 0.001666667 kWh |
| 7 kWh = 25,200 kJ | 7 kJ = 0.001944444 kWh |
| 8 kWh = 28,800 kJ | 8 kJ = 0.002222222 kWh |
| 9 kWh = 32,400 kJ | 9 kJ = 0.0025 kWh |
| 10 kWh = 36,000 kJ | 10 kJ = 0.002777778 kWh |
| 12 kWh = 43,200 kJ | 12 kJ = 0.003333333 kWh |
| 15 kWh = 54,000 kJ | 15 kJ = 0.004166667 kWh |
| 20 kWh = 72,000 kJ | 20 kJ = 0.005555556 kWh |
| 25 kWh = 90,000 kJ | 25 kJ = 0.006944444 kWh |
| 30 kWh = 108,000 kJ | 30 kJ = 0.008333333 kWh |
| 40 kWh = 144,000 kJ | 40 kJ = 0.01111111 kWh |
| 50 kWh = 180,000 kJ | 50 kJ = 0.01388889 kWh |
| 75 kWh = 270,000 kJ | 75 kJ = 0.02083333 kWh |
| 100 kWh = 360,000 kJ | 100 kJ = 0.02777778 kWh |
| 150 kWh = 540,000 kJ | 150 kJ = 0.04166667 kWh |
| 200 kWh = 720,000 kJ | 200 kJ = 0.05555556 kWh |
| 250 kWh = 900,000 kJ | 250 kJ = 0.06944444 kWh |
| 500 kWh = 1,800,000 kJ | 500 kJ = 0.1388889 kWh |
| 1000 kWh = 3,600,000 kJ | 1000 kJ = 0.2777778 kWh |
Kilowatt-hour vs Kilojoule: which is bigger?
A kilowatt-hour is the larger unit: one kilowatt-hour equals 3,600 kilojoules. Put another way, you need 3,600 kilojoules to make a single kilowatt-hour.
What is a Kilowatt-hour? History, origin and usage
The kilowatt-hour — 1,000 watt-hours — became the universal trading unit of electrical energy as power grids spread in the late 19th and early 20th centuries. It rests on the watt, named after James Watt, scaled up to the household level.
The kilowatt-hour is the “unit” your electricity meter records and your utility bills you for; appliance running costs are worked out by multiplying an item’s kilowatt rating by the hours it runs and the price per kWh. It is the single most important energy unit in domestic and commercial energy.
One kilowatt-hour equals exactly 3.6 megajoules (3,600,000 joules), because a kilowatt is 1,000 joules per second and an hour is 3,600 seconds. Running a 1,000-watt appliance for one hour consumes exactly one kilowatt-hour — the figure people informally call a “unit” of electricity.
What is a Kilojoule? History, origin and usage
The kilojoule is simply 1,000 joules, formed with the SI “kilo” prefix, and it inherits the joule’s heritage from James Prescott Joule’s heat experiments. It became the practical everyday multiple of the joule because single joules are inconveniently small for food, fuel and exercise energy.
The kilojoule is the energy figure on nutrition labels across Europe, Australia and many other countries, usually printed alongside (or instead of) kilocalories. It is also handy for stating the energy of small chemical reactions, batteries and household tasks.
Australia and New Zealand use kilojoules almost exclusively for food energy, so a chocolate bar there is rated in kJ rather than Calories. One food “Calorie” (a kilocalorie) is about 4.184 kJ, which is why kilojoule figures on labels look roughly four times larger than the familiar calorie counts.
Convert 1 Kilowatt-hour to other units
It can help to see a kilowatt-hour next to the other units it is commonly compared with. One kilowatt-hour (kWh) is equal to:
| 1 Kilowatt-hour equals | Unit |
|---|---|
| 3,600,000 J | Joule |
| 3,600,000 N·m | Newton-metre |
| 3,600 kJ | Kilojoule |
| 3.6 MJ | Megajoule |
| 1,000 Wh | Watt-hour |
| 0.001 MWh | Megawatt-hour |
| 2,655,224 ft·lbf | Foot-pound |
| 22,469,430,000,000,000,000 MeV | Megaelectronvolt |
| 860,420.7 cal | Calorie |
| 860.4207 kcal | Kilocalorie |
| 3,412.142 BTU | British Thermal Unit |
Convert 1 Kilojoule to other units
One kilojoule (kJ) is equal to:
| 1 Kilojoule equals | Unit |
|---|---|
| 1,000 J | Joule |
| 1,000 N·m | Newton-metre |
| 0.001 MJ | Megajoule |
| 0.2777778 Wh | Watt-hour |
| 0.0002777778 kWh | Kilowatt-hour |
| 0.0000002777778 MWh | Megawatt-hour |
| 737.5621 ft·lbf | Foot-pound |
| 6,241,509,000,000,000 MeV | Megaelectronvolt |
| 239.0057 cal | Calorie |
| 0.2390057 kcal | Kilocalorie |
| 0.9478171 BTU | British Thermal Unit |
Tips for converting Kilowatt-hour to Kilojoule
- To go from kilowatt-hour to kilojoule, multiply by 3,600; to go back, divide by 3,600 (or multiply by 0.0002777778).
- For a quick mental estimate, remember that 1 kilowatt-hour ≈ 3,600 kilojoule, so 10 kilowatt-hour ≈ 36,000 kilojoule.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this Kilowatt-hour to Kilojoule converter
Type a number into the Kilowatt-hour field and the equivalent in Kilojoule appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Kilojoule field to convert the other way (kilojoule to kilowatt-hour). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 kWh = 3,600 kJ), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for kilowatt-hour-to-kilojoule conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
- NIST — Definitions of the SI base units — the US National Institute of Standards and Technology reference for the SI base units, used here as an independent cross-check on the base-unit definition.
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Frequently asked questions
- How many kilojoule are in 1 kilowatt-hour?
- 1 kilowatt-hour = 3,600 kilojoule (kJ). To convert any number of kilowatt-hour to kilojoule, multiply by 3,600.
- How do I convert kilowatt-hour to kilojoule?
- Multiply the number of kilowatt-hour by 3,600. For example, 10 kilowatt-hour = 10 × 3,600 = 36,000 kilojoule, and 25 kilowatt-hour = 90,000 kilojoule.
- How many kilowatt-hour are in 1 kilojoule?
- 1 kilojoule = 0.0002777778 kilowatt-hour. So to convert kilojoule back to kilowatt-hour, multiply by 0.0002777778.
- What is the formula to convert kilowatt-hour to kilojoule?
- kilojoule = kilowatt-hour × 3,600. The reverse formula is kilowatt-hour = kilojoule × 0.0002777778.
- How much is 100 kilowatt-hour in kilojoule?
- 100 kilowatt-hour = 360,000 kilojoule. (And 1000 kilowatt-hour = 3,600,000 kilojoule.)
- Which is bigger, a kilowatt-hour or a kilojoule?
- A kilowatt-hour is larger: 1 kilowatt-hour = 3,600 kilojoule.
- Is this kilowatt-hour to kilojoule converter accurate?
- Yes — every value is computed from the exact 3,600 kJ per kWh factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert kilojoule to kilowatt-hour too?
- Yes. The converter works both ways — enter a value in either field. 1 kilojoule = 0.0002777778 kilowatt-hour.