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: Calorie = Kilowatt-Hour × 860,400
Multiply any kilowatt-hour value by 860,400 to get calorie.
Reverse: Kilowatt-Hour = Calorie × 1.1622e-6
Common kilowatt-hour values — factor: 1 kWh = 860,400 cal
| Kilowatt-Hour (kWh) | Calorie (cal) | Context |
|---|---|---|
| 0.001 kWh | 860.4 cal | 1 Wh |
| 0.01 kWh | 8,604 cal | 10 Wh |
| 0.1 kWh | 8.604e+04 cal | Phone charge |
| 0.5 kWh | 4.302e+05 cal | Half kWh |
| 1 kWh | 8.604e+05 cal | 1 kWh |
| 5 kWh | 4.302e+06 cal | 5 kWh |
| 10 kWh | 8.604e+06 cal | Washing machine |
| 30 kWh | 2.581e+07 cal | Daily home use |
| 100 kWh | 8.604e+07 cal | Monthly fraction |
| 500 kWh | 4.302e+08 cal | EV range |
| 1,000 kWh | 8.604e+08 cal | Monthly home |
| 1e+04 kWh | 8.604e+09 cal | Annual home |
| 1e+05 kWh | 8.604e+10 cal | Large commercial |
| 1e+06 kWh | 8.604e+11 cal | Small factory |
| 1.000e+09 kWh | 8.604e+14 cal | Power plant day |
1 kWh = 860,400 cal. Memorize for instant estimates.
Use 860,400 as a quick mental multiplier.
Multiply result by 1.1622e-6 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 calorie (cal) was defined in 1824 as the heat needed to raise 1 gram of water by 1°C. There are two versions: the small calorie (cal = 4.184 J) and the large calorie or kilocalorie (kcal = 4,184 J), which is the 'Calorie' used in nutrition.
The calorie remains standard in chemistry for heat of reaction measurements. In the US, food packaging uses 'Calories' (with capital C) which are actually kilocalories — a persistent source of confusion.
Interesting fact: The confusion between cal and kcal means that a food label saying '200 Calories' actually means 200 kcal = 200,000 cal = 836,800 joules. The SI unit for food energy is the kilojoule.
Converting kilowatt-hour to calorie 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 = 4.302e+06 cal and 10 kWh = 8.604e+06 cal. Reverse: 1 cal = 1.1622e-6 kWh. Exact factor: 1 kWh = 860,400 cal.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.