10 J to kWh — 10 joules in kilowatt-hours
Exact 10 ÷ 3,600,000 = 0.000002777778
10 joules in other units
| Kilojoules | 0.01 | kJ |
|---|---|---|
| Megajoules | 0.00001 | MJ |
| Watt-hours | 0.002777777778 | Wh |
| Kilowatt-hours | 0.000002777778 | kWh |
| Calories | 2.390057 | cal |
| Kilocalories | 0.002390057361 | kcal |
| British thermal units | 0.009478171203 | BTU |
| Therms | 9.4782e-8 | thm |
| Foot-pounds | 7.375621 | ft·lbf |
| Electronvolts | 62,415,090,744,607,629,312 | eV |
J to kWh at a glance
| Joules | Kilowatt-hours |
|---|---|
| 1 J | 2.7778e-7 kWh |
| 2 J | 5.5556e-7 kWh |
| 3 J | 8.3333e-7 kWh |
| 5 J | 0.000001388889 kWh |
| 10 J | 0.000002777778 kWh |
| 20 J | 0.000005555556 kWh |
| 25 J | 0.000006944444 kWh |
| 50 J | 0.000013888889 kWh |
| 100 J | 0.000027777778 kWh |
| 250 J | 0.000069444444 kWh |
| 500 J | 0.000138888889 kWh |
| 1,000 J | 0.000277777778 kWh |
How to convert joules to kilowatt-hours
Multiply by 2.7778e-7 — one joule is 2.7778e-7 kilowatt-hours. That factor is exact: it comes from the definition of the units rather than from a measurement, so it will not change and does not need rounding.
Working 10 ÷ 3,600,000 = 0.000002777778
What these units are
The joule and the kilowatt-hour are covered in the energy unit guide, along with every other unit on this page.
Questions
How many kilowatt-hours are in a joule?
One joule is 2.7778e-7 kilowatt-hours. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 10 joules in kilowatt-hours?
10 joules is 0.000002777778 kilowatt-hours. The working is 10 ÷ 3,600,000 = 0.000002777778.
Is a food Calorie the same as a calorie?
No — it is a thousand of them. The Calorie on a nutrition label is a kilocalorie, written with a capital C in principle and almost never in practice. A 250 Calorie chocolate bar holds 250,000 physics calories, or about 1,046 kilojoules, which is why European labels quote kJ alongside.
What does a kilowatt-hour actually represent?
One kilowatt drawn for one hour — a 1,000 W heater running for sixty minutes, or a 100 W bulb for ten hours. It is the unit your electricity bill is priced in, and it equals exactly 3.6 million joules.
How much energy is one BTU?
Roughly the heat needed to raise one pound of water by one degree Fahrenheit — about 1,055 joules, or the energy in a single kitchen match. Air conditioners are rated in BTU per hour, where a 12,000 BTU/h unit is one "ton" of cooling and draws around 3.5 kW of heat.
Why is the electronvolt so small?
Because it is sized for single particles: it is the energy one electron picks up crossing a one-volt potential difference. At about 1.6 × 10⁻¹⁹ joules it would be absurd for anything larger, which is precisely why particle physics uses it instead of dragging around twenty leading zeros.