Metric Conversions
Metric Conversions

Joules (J)

The joule is the SI unit of energy defined as the work done when a force of one newton moves an object one meter in the direction of the force. It equals one kilogram meter squared per second squared (kg·m²/s²). This definition aligns with the International System of Units as standardized by the BIPM [bipm-si-brochure].

Origin

The joule is named after James Prescott Joule, a 19th-century physicist who studied energy conservation. It was officially adopted as a unit of energy by the CGPM in 1948 to unify energy measurement standards internationally [cgpm-resolutions].

Worldwide Use

Joules are used worldwide in physics, engineering, and electrical industries to quantify energy, work, and heat. Countries using the SI system, including those in Europe, Asia, and the Americas, rely on joules for scientific and industrial applications [nist-si-guide].

Common References

  • A single chocolate bar contains about 2,000,000 joules of energy
  • An average lightning strike releases around 1 billion joules
  • Lifting a 1 kg object 1 meter requires approximately 10 joules
  • One watt of power used for one second equals one joule
  • A standard AA battery stores about 10,000 joules
Joules → Kilojoules1 J = 0.001 kJJoules → Megajoules1 J = 0 MJJoules → Gigajoules1 J = 0 GJJoules → Calories1 J = 0.239 calJoules → Kilocalories1 J = 0.0002 kcalJoules → Watt Hours1 J = 0.0003 WhJoules → Kilowatt Hours1 J = 0 kWhJoules → Megawatt Hours1 J = 0 MWhJoules → Electron Volts1 J = 6,241,509,074,460,763,000 eVJoules → British Thermal Units1 J = 0.0009 BTUJoules → Therms1 J = 0 thmJoules → Foot-Pounds1 J = 0.7376 ft⋅lbfJoules → Ergs1 J = 10,000,000 ergJoules → Watts1 J = 1 WJoules → Kilowatts1 J = 0.001 kWJoules → Megawatts1 J = 0 MWJoules → Gigawatts1 J = 0 GWJoules → Horsepower1 J = 0.0013 hpJoules → Metric Horsepower1 J = 0.0014 PSJoules → Foot-Pounds per Minute1 J = 44.2537 ft⋅lbf/minJoules → Foot-Pounds per Second1 J = 0.7376 ft⋅lbf/sJoules → BTU per Hour1 J = 3.4121 BTU/hJoules → BTU per Minute1 J = 0.0569 BTU/minJoules → Tons of Refrigeration1 J = 0.0003 TRJoules → Milliwatts1 J = 1,000 mWJoules → Microwatts1 J = 1,000,000 µWJoules → Nanowatts1 J = 1,000,000,000 nWJoules → Terawatts1 J = 0 TWJoules → Petajoules1 J = 0 PJJoules → Exajoules1 J = 0 EJJoules → Calories (Nutritional)1 J = 0.0002 CalJoules → Tons of TNT1 J = 0 tTNTJoules → Kilotons of TNT1 J = 0 ktTNTJoules → Megatons of TNT1 J = 0 MtTNTJoules → Barrels of Oil Equivalent1 J = 0 BOE