Joules (J) to Ergs (erg) Conversion

Joules

The joule (J) is the SI derived unit of energy, work, and heat, defined as the work done when a force of one newton displaces an object by one metre (J = N·m = kg·m²·s⁻²). Named after James Prescott Joule, who established the mechanical equivalent of heat in the 1840s, the joule unifies all forms of energy — mechanical, thermal, electrical, chemical, and nuclear — under one framework. One joule is small: lifting an apple (≈100 g) one metre requires about 1 joule, while a human at rest metabolises approximately 80 joules per second.

Ergs

The erg is a unit of energy in the CGS (centimetre-gram-second) system, equal to exactly 10⁻⁷ joules. The word derives from the Greek ergon (work). Though largely superseded by the joule in modern science, the erg persists in astrophysics — stellar luminosities and gamma-ray burst energies are sometimes expressed in ergs — and in classical physics texts. One erg is approximately the energy required to move a mosquito by 1 cm. The total energy released by the Sun per second is approximately 3.8 × 10³³ ergs.

Convert Joules (J) to other units of Energy