BTU to Kilojoule Converter

A British Thermal Unit (BTU) is a unit of energy equal to approximately 1,055 joules. It represents the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit at standard atmospheric pressure.

The BTU was developed in the 19th century as part of the British Imperial system for measuring heat energy. It became standard in heating, ventilation, and air conditioning (HVAC) applications in countries using imperial units, particularly for rating heating and cooling equipment capacity.

BTUs are extensively used in the United States for HVAC system ratings, heating and cooling equipment specifications, and energy content of fuels. They're standard for furnace output ratings, air conditioner capacity, water heater specifications, and natural gas energy content measurements.

A kilojoule (kJ) is a unit of energy equal to one thousand joules (10³ J). It's commonly used for measuring food energy content, small-scale mechanical work, and energy in chemical reactions.

The kilojoule became widely adopted in nutrition and food science as many countries moved away from calories to metric energy units. It was officially adopted for food labeling in many countries as part of metrication efforts, providing a more scientifically consistent energy measurement.

Kilojoules are extensively used in food and nutrition labeling, exercise and fitness calculations, chemical reaction energy measurements, and small-scale engineering applications. They're mandatory on food labels in many countries and are standard in sports science and metabolism studies.