Convert Joules to Ergs

Convert Joules (J) to Ergs (erg) instantly and accurately.

Conversion Formula

erg = J × 10000000

About Joules

The joule (J) is the SI unit of energy, defined as one newton acting through one metre (1 J = 1 N·m = 1 kg·m²/s²). Named after James Prescott Joule, whose 1840s paddle-wheel experiments established the mechanical equivalent of heat (~4.15 J = 1 calorie). One joule is modest: it lifts a 100 g apple by 1 m, heats 0.239 mL of water by 1°C, or powers a 1 W LED for 1 second. Daily adult resting metabolism is ~6-9 MJ. 1 J = 1 W·s = 0.23901 cal = 9.4782 × 10⁻⁴ BTU = 2.7778 × 10⁻⁷ kWh.

About Ergs

An erg is the CGS unit of energy - the work done by one dyne through one centimetre - exactly 10⁻⁷ J. Despite SI adoption, the erg persists in astrophysics: the Sun's luminosity is 3.828 × 10³³ erg/s; gamma-ray burst isotropic energies are quoted in units of 10⁵¹ erg ('one foe'). Surface tension of water is 72.8 dyn/cm; the work to create 1 cm² of new water-air interface is 72.8 erg. Earthquake seismic moment M₀ is in dyn·cm = erg; the 2004 Boxing Day earthquake had M₀ ≈ 10²³ J = 10³⁰ erg. 1 erg = 10⁻⁷ J = 624.15 eV.

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