Convert energy units — joules, calories, kilowatt-hours, BTU, kilojoules.
| Unit | Name | Value |
|---|---|---|
| J | Joule | 3600000 |
| kJ | Kilojoule | 3600 |
| cal | Calorie | 860420.65 |
| kcal | Kilocalorie (Cal) | 860.42065 |
| BTU | BTU | 3412.1282 |
Formula: Kilojoule = Kilowatt-Hour × 3600
Multiply any kilowatt-hour value by 3600 to get kilojoule.
Reverse: Kilowatt-Hour = Kilojoule × 0.0002778
Common kilowatt-hour values — factor: 1 kWh = 3600 kJ
| Kilowatt-Hour (kWh) | Kilojoule (kJ) | Context |
|---|---|---|
| 0.001 kWh | 3.6 kJ | 1 Wh |
| 0.01 kWh | 36 kJ | 10 Wh |
| 0.1 kWh | 360 kJ | Phone charge |
| 0.5 kWh | 1,800 kJ | Half kWh |
| 1 kWh | 3,600 kJ | 1 kWh |
| 5 kWh | 1.8e+04 kJ | 5 kWh |
| 10 kWh | 3.6e+04 kJ | Washing machine |
| 30 kWh | 1.08e+05 kJ | Daily home use |
| 100 kWh | 3.6e+05 kJ | Monthly fraction |
| 500 kWh | 1.8e+06 kJ | EV range |
| 1,000 kWh | 3.6e+06 kJ | Monthly home |
| 1e+04 kWh | 3.6e+07 kJ | Annual home |
| 1e+05 kWh | 3.6e+08 kJ | Large commercial |
| 1e+06 kWh | 3.600e+09 kJ | Small factory |
| 1.000e+09 kWh | 3.600e+12 kJ | Power plant day |
1 kWh = 3600 kJ. Memorize for instant estimates.
Use 3600 as a quick mental multiplier.
Multiply result by 0.0002778 to recover the original kWh value.
Reads monthly bills and compares appliance energy use in kWh.
Sizes solar systems based on kWh consumption and production estimates.
Tracks charging cost and range efficiency in kWh per 100 km.
Measures building energy consumption and identifies savings in kWh.
Plans grid capacity, demand response, and billing in kWh and MWh.
Monitors real-time appliance consumption in kWh via smart meters.
The kilowatt-hour (kWh) is the commercial unit of electrical energy, equal to the energy consumed by a 1,000-watt appliance in one hour (3,600,000 joules). It became standard with the growth of the electrical grid in the late 19th century.
Electricity bills worldwide are denominated in kWh. A typical household uses 300–1,000 kWh per month. An electric car uses about 15–25 kWh per 100 km. Solar panels generate 250–400 kWh per year per panel.
Interesting fact: The average price of electricity in the US is about $0.12 per kWh. One kWh can run a 100W light bulb for 10 hours, charge a smartphone about 100 times, or power a laptop for 2-3 days.
The kilojoule (kJ) equals 1,000 joules and is the practical energy unit for food, chemistry, and heating applications in metric countries. Food energy labels in Australia, Europe, and most of the world use kilojoules.
A dietary calorie (kcal) equals 4.184 kJ. A can of soda contains about 600 kJ. The specific heat of water (4.184 kJ/kg·°C) means heating 1 liter of water by 1°C requires 4.184 kJ.
Interesting fact: An average adult needs about 8,000-10,000 kJ (2,000-2,400 kcal) per day. Running a marathon burns approximately 12,500 kJ.
Converting kilowatt-hour to kilojoule is common across energy, nutrition, engineering, and science. Different sectors use different energy units — joules in physics, kcal in nutrition, kWh in electricity, and BTU in HVAC — making accurate conversion essential for cross-disciplinary work and international comparisons.
Quick reference: 5 kWh = 18,000 kJ and 10 kWh = 36,000 kJ. Reverse: 1 kJ = 0.0002778 kWh. Exact factor: 1 kWh = 3600 kJ.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.