Joule to BTU Converter

A joule (J) is the SI base unit of energy, defined as the energy expended when applying a force of one newton through a distance of one meter. It represents the fundamental measure of energy, work, and heat in the International System of Units.

The joule was named after English physicist James Prescott Joule in 1889, who studied the relationship between heat and mechanical work. It was adopted as the SI unit of energy in 1960, replacing various other energy units and providing a unified measure for all forms of energy.

Joules are universally used in scientific calculations, physics education, engineering applications, and energy measurements. They're fundamental to all energy calculations in science and engineering, from atomic-scale processes to mechanical systems, and are the basis for all other energy units.

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.