Calorie to Kilowatt Hour Converter

A calorie (cal), also called a small calorie or gram calorie, is a unit of energy equal to approximately 4.184 joules. It represents the energy needed to raise the temperature of one gram of water by one degree Celsius at standard atmospheric pressure.

The calorie was defined by French chemist Nicolas Clément in 1824 as a unit for measuring heat. It was widely used in chemistry and physics for calorimetry and thermodynamics before being largely replaced by the joule in scientific applications, though it remains in use for food energy.

Calories are primarily used in chemistry for small-scale energy measurements, in some scientific literature, and occasionally in food and nutrition contexts. However, they've been largely replaced by joules in scientific applications and by kilocalories (food calories) in nutrition.

A kilowatt-hour (kWh) is a unit of energy equal to the energy consumed by a device with a power rating of one kilowatt operating for one hour. It equals 3.6 megajoules and is the standard unit for measuring electrical energy consumption.

The kilowatt-hour was developed with the commercialization of electricity in the late 19th century. It provided a practical way for electric utilities to measure and bill for electrical energy consumption, becoming the standard unit for electrical energy trading worldwide.

Kilowatt-hours are universally used for measuring and billing electrical energy consumption in homes, businesses, and industries. They're found on every electricity bill, used in energy efficiency ratings for appliances, and are standard in renewable energy system specifications and grid energy trading.