Energy
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Convert between common energy units: joules, calories, kilocalories, and kilowatt-hours. Energy quantifies capacity to do work or transfer heat. The joule (J) is the SI unit. Nutrition labels use kilocalories (often labeled “Calories” with a capital C). Food calories are actually kcal. Electricity bills use kilowatt-hours (kWh): one kWh is the energy of 1 kW over one hour. The small calorie (cal) is about 4.184 J (thermochemical). These contexts—physics, diet, and utilities—use different scales; converting helps you compare exercise burn, food intake, and appliance usage. Calculations use standard thermochemical calories unless noted. Everything runs client-side for privacy.
Supported units: joule (J), calorie (cal), kilocalorie (kcal), kilowatt-hour (kWh).
All units for this value
| Unit | Result |
|---|---|
| joule | 0 J |
| calorie | 0 cal |
| kilocalorie | 0 kcal |
| kilowatt-hour | 0 kWh |
Brief explanation: joule to calorie
1 cal = 4.184 J; 1 kcal = 4184 J; 1 kWh = 3,600,000 J. Nutrition “Calories” are kcal.
Other converters
Most common Energy conversions
Common: kWh to MJ (bills), kcal to kJ (nutrition), J to cal (lab).
Quick reference – Energy
1 kWh = 3.6×10⁶ J | 1 kcal = 4184 J | 1 cal = 4.184 J
FAQ
Common Use Cases
- ✓Nutrition
- ✓Electricity bills
- ✓Physics
- ✓Exercise