J · kJ · cal · kcal · Wh · kWh · BTU · eV
Free Energy Converter
Convert energy units instantly — joules, kilojoules, kilowatt-hours, calories, kilocalories, BTU, watt-hours, electron volts. Free, symmetrical.
Why symmetrical conversion?
How This Converter Works
Energy is measured in many units across different fields — joules in physics, calories in nutrition, BTU in heating/cooling, and kWh on electricity bills. All 8 energy units update simultaneously.
Quick reference
Common Conversions
| Joules (J) | kWh | Calories (kcal) | Context |
|---|---|---|---|
| 4.184 J | 0.0000012 kWh | 0.001 kcal | One small calorie (cal) |
| 4,184 J | 0.00116 kWh | 1 kcal | One food Calorie |
| 1,055 J | 0.000293 kWh | 0.252 kcal | One BTU |
| 3,600,000 J | 1.0 kWh | 860 kcal | One kilowatt-hour |
| 8,368,000 J | 2.324 kWh | 2,000 kcal | Daily human energy need |
FAQ
Frequently Asked Questions
1What is the difference between a calorie and a kilocalorie?
A small calorie (cal) is the energy to heat 1g of water by 1°C. A kilocalorie (kcal) = 1,000 cal. Nutritional 'Calories' (capital C) on food labels are actually kilocalories.
2How do I convert kWh to joules?
Multiply by 3,600,000. One kilowatt-hour = 3.6 × 10⁶ joules. kWh is used for electricity billing, while joules are the SI unit.
3What is a BTU?
BTU (British Thermal Unit) is the energy required to raise one pound of water by 1°F. It is used in heating, cooling, and HVAC specifications in the US.
4How many joules is 1 electron volt?
One electron volt (eV) equals 1.602 × 10⁻¹⁹ joules. It is used in atomic and particle physics to measure energy at the subatomic scale.
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