Convert Joule to Kilowatt-hour
1 joule = 0.0000002777778 kilowatt-hour (kWh). For example, 10 joule = 0.000002777778 kilowatt-hour and 100 joule = 0.00002777778 kilowatt-hour. Type any value below to convert joule to kilowatt-hour both ways — it runs entirely in your browser.
Quick answer: Joule to Kilowatt-hour
1 Joule = 0.0000002777778 Kilowatt-hour (J → kWh). To convert joule to kilowatt-hour, multiply by 0.0000002777778. To convert kilowatt-hour to joule, multiply by 3,600,000. 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 joule-to-kilowatt-hour questions.
How to convert Joule to Kilowatt-hour
To convert joule to kilowatt-hour, multiply the number of joule by the conversion factor 0.0000002777778, because 1 J = 0.0000002777778 kWh. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 kWh = 3,600,000 J, so you divide by 0.0000002777778 (or multiply by 3,600,000) to turn kilowatt-hour back into joule.
kWh = J × 0.0000002777778 ·
J = kWh × 3,600,000
- Write down the value you want to convert, in joule.
- Multiply it by 0.0000002777778.
- The result is the same area/length/quantity expressed in kilowatt-hour.
Joule to Kilowatt-hour — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 joule is 0.000001388889 kilowatt-hour because 5 J × 0.0000002777778 = 0.000001388889 kWh.
| Joule | Calculation | Kilowatt-hour |
|---|---|---|
| 1 J | 1 J × 0.0000002777778 = 0.0000002777778 kWh | 0.0000002777778 kWh |
| 2 J | 2 J × 0.0000002777778 = 0.0000005555556 kWh | 0.0000005555556 kWh |
| 3 J | 3 J × 0.0000002777778 = 0.0000008333333 kWh | 0.0000008333333 kWh |
| 5 J | 5 J × 0.0000002777778 = 0.000001388889 kWh | 0.000001388889 kWh |
| 7 J | 7 J × 0.0000002777778 = 0.000001944444 kWh | 0.000001944444 kWh |
| 10 J | 10 J × 0.0000002777778 = 0.000002777778 kWh | 0.000002777778 kWh |
| 12 J | 12 J × 0.0000002777778 = 0.000003333333 kWh | 0.000003333333 kWh |
| 15 J | 15 J × 0.0000002777778 = 0.000004166667 kWh | 0.000004166667 kWh |
| 20 J | 20 J × 0.0000002777778 = 0.000005555556 kWh | 0.000005555556 kWh |
| 25 J | 25 J × 0.0000002777778 = 0.000006944444 kWh | 0.000006944444 kWh |
| 50 J | 50 J × 0.0000002777778 = 0.00001388889 kWh | 0.00001388889 kWh |
| 100 J | 100 J × 0.0000002777778 = 0.00002777778 kWh | 0.00002777778 kWh |
Common Joule to Kilowatt-hour conversions
These are the joule-to-kilowatt-hour values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 joule = 0.0000002777778 kilowatt-hour
- 2 joule = 0.0000005555556 kilowatt-hour
- 2.5 joule = 0.0000006944444 kilowatt-hour
- 3 joule = 0.0000008333333 kilowatt-hour
- 4 joule = 0.000001111111 kilowatt-hour
- 5 joule = 0.000001388889 kilowatt-hour
- 6 joule = 0.000001666667 kilowatt-hour
- 7 joule = 0.000001944444 kilowatt-hour
- 8 joule = 0.000002222222 kilowatt-hour
- 9 joule = 0.0000025 kilowatt-hour
- 10 joule = 0.000002777778 kilowatt-hour
- 12 joule = 0.000003333333 kilowatt-hour
- 15 joule = 0.000004166667 kilowatt-hour
- 20 joule = 0.000005555556 kilowatt-hour
- 25 joule = 0.000006944444 kilowatt-hour
- 30 joule = 0.000008333333 kilowatt-hour
- 50 joule = 0.00001388889 kilowatt-hour
- 75 joule = 0.00002083333 kilowatt-hour
- 100 joule = 0.00002777778 kilowatt-hour
- 200 joule = 0.00005555556 kilowatt-hour
- 500 joule = 0.0001388889 kilowatt-hour
- 1000 joule = 0.0002777778 kilowatt-hour
Joule to Kilowatt-hour conversion chart (both directions)
The chart below converts joule to kilowatt-hour and kilowatt-hour to joule side by side, so it works whichever way you need. 1 joule = 0.0000002777778 kilowatt-hour, and 1 kilowatt-hour = 3,600,000 joule.
| Joule → Kilowatt-hour | Kilowatt-hour → Joule |
|---|---|
| 0.25 J = 0.00000006944444 kWh | 0.25 kWh = 900,000 J |
| 0.5 J = 0.0000001388889 kWh | 0.5 kWh = 1,800,000 J |
| 1 J = 0.0000002777778 kWh | 1 kWh = 3,600,000 J |
| 2 J = 0.0000005555556 kWh | 2 kWh = 7,200,000 J |
| 3 J = 0.0000008333333 kWh | 3 kWh = 10,800,000 J |
| 4 J = 0.000001111111 kWh | 4 kWh = 14,400,000 J |
| 5 J = 0.000001388889 kWh | 5 kWh = 18,000,000 J |
| 6 J = 0.000001666667 kWh | 6 kWh = 21,600,000 J |
| 7 J = 0.000001944444 kWh | 7 kWh = 25,200,000 J |
| 8 J = 0.000002222222 kWh | 8 kWh = 28,800,000 J |
| 9 J = 0.0000025 kWh | 9 kWh = 32,400,000 J |
| 10 J = 0.000002777778 kWh | 10 kWh = 36,000,000 J |
| 12 J = 0.000003333333 kWh | 12 kWh = 43,200,000 J |
| 15 J = 0.000004166667 kWh | 15 kWh = 54,000,000 J |
| 20 J = 0.000005555556 kWh | 20 kWh = 72,000,000 J |
| 25 J = 0.000006944444 kWh | 25 kWh = 90,000,000 J |
| 30 J = 0.000008333333 kWh | 30 kWh = 108,000,000 J |
| 40 J = 0.00001111111 kWh | 40 kWh = 144,000,000 J |
| 50 J = 0.00001388889 kWh | 50 kWh = 180,000,000 J |
| 75 J = 0.00002083333 kWh | 75 kWh = 270,000,000 J |
| 100 J = 0.00002777778 kWh | 100 kWh = 360,000,000 J |
| 150 J = 0.00004166667 kWh | 150 kWh = 540,000,000 J |
| 200 J = 0.00005555556 kWh | 200 kWh = 720,000,000 J |
| 250 J = 0.00006944444 kWh | 250 kWh = 900,000,000 J |
| 500 J = 0.0001388889 kWh | 500 kWh = 1,800,000,000 J |
| 1000 J = 0.0002777778 kWh | 1000 kWh = 3,600,000,000 J |
Joule vs Kilowatt-hour: which is bigger?
A kilowatt-hour is the larger unit: one kilowatt-hour equals 3,600,000 joules. Put another way, you need 3,600,000 joules to make a single kilowatt-hour.
What is a Joule? History, origin and usage
The joule is named after the English physicist James Prescott Joule (1818-1889), a Salford brewer’s son who, through painstaking experiments in the 1840s, measured the mechanical equivalent of heat and showed that work and heat are interchangeable forms of energy. The name was proposed by Wilhelm Siemens at an 1882 British Association meeting, and the joule was adopted as an international unit at the 1889 International Electrical Congress — just weeks before Joule himself died.
As the SI unit of energy, the joule underpins all of physics and engineering, measuring mechanical work, heat and electrical energy alike (one joule is also one watt-second). It appears on European food labels (usually as kilojoules), in battery specifications, and anywhere energy must be stated in coherent SI units.
One joule is roughly the energy needed to lift a small apple (about 100 grams) one metre against gravity, or the kinetic energy of a 56-gram tennis ball travelling about 6 m/s. Because one joule equals one newton-metre, the joule is dimensionally identical to the newton-metre of torque, yet the two describe different physical quantities.
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.
Convert 1 Joule to other units
It can help to see a joule next to the other units it is commonly compared with. One joule (J) is equal to:
| 1 Joule equals | Unit |
|---|---|
| 1 N·m | Newton-metre |
| 0.001 kJ | Kilojoule |
| 0.000001 MJ | Megajoule |
| 0.0002777778 Wh | Watt-hour |
| 0.0000002777778 kWh | Kilowatt-hour |
| 0.0000000002777778 MWh | Megawatt-hour |
| 0.7375621 ft·lbf | Foot-pound |
| 6,241,509,000,000 MeV | Megaelectronvolt |
| 0.2390057 cal | Calorie |
| 0.0002390057 kcal | Kilocalorie |
| 0.0009478171 BTU | British Thermal Unit |
Convert 1 Kilowatt-hour to other units
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 |
Tips for converting Joule to Kilowatt-hour
- To go from joule to kilowatt-hour, multiply by 0.0000002777778; to go back, divide by 0.0000002777778 (or multiply by 3,600,000).
- For a quick mental estimate, remember that 1 joule ≈ 0.0000002777778 kilowatt-hour, so 10 joule ≈ 0.000002777778 kilowatt-hour.
- 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 Joule to Kilowatt-hour converter
Type a number into the Joule field and the equivalent in Kilowatt-hour 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 Kilowatt-hour field to convert the other way (kilowatt-hour to joule). 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 J = 0.0000002777778 kWh), 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 joule-to-kilowatt-hour 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 kilowatt-hour are in 1 joule?
- 1 joule = 0.0000002777778 kilowatt-hour (kWh). To convert any number of joule to kilowatt-hour, multiply by 0.0000002777778.
- How do I convert joule to kilowatt-hour?
- Multiply the number of joule by 0.0000002777778. For example, 10 joule = 10 × 0.0000002777778 = 0.000002777778 kilowatt-hour, and 25 joule = 0.000006944444 kilowatt-hour.
- How many joule are in 1 kilowatt-hour?
- 1 kilowatt-hour = 3,600,000 joule. So to convert kilowatt-hour back to joule, multiply by 3,600,000.
- What is the formula to convert joule to kilowatt-hour?
- kilowatt-hour = joule × 0.0000002777778. The reverse formula is joule = kilowatt-hour × 3,600,000.
- How much is 100 joule in kilowatt-hour?
- 100 joule = 0.00002777778 kilowatt-hour. (And 1000 joule = 0.0002777778 kilowatt-hour.)
- Which is bigger, a joule or a kilowatt-hour?
- A kilowatt-hour is larger: 1 kilowatt-hour = 3,600,000 joule.
- Is this joule to kilowatt-hour converter accurate?
- Yes — every value is computed from the exact 0.0000002777778 kWh per J factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert kilowatt-hour to joule too?
- Yes. The converter works both ways — enter a value in either field. 1 kilowatt-hour = 3,600,000 joule.