Convert between different energy units including joules, calories, kilowatt-hours, electron volts and more with precise calculations and instant results.
The calorie was originally defined as the amount of energy needed to raise the temperature of 1 gram of water by 1°C. The food Calorie (with a capital C) we commonly see on nutrition labels is actually a kilocalorie, or 1,000 small calories.
An electron volt (eV) is the amount of energy gained by an electron moving across an electric potential difference of one volt. It's commonly used in atomic and nuclear physics and is extremely small—about 1.602 × 10^(-19) joules.
The sun produces approximately 3.8 × 10^26 joules of energy per second through nuclear fusion. This is equivalent to about 9.1 × 10^22 kilowatt-hours—more energy than humanity has used throughout its entire history.
A typical slice of bread contains about 80 kilocalories of energy. This is enough energy to power a 60-watt light bulb for about 80 minutes or to lift an average human about 104 meters (341 feet) straight up.