Convert Ergs to Joules
1 erg equals 1 × 10⁻⁷ joules (J).
1 erg = 1e-7 J
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk erg to joule converter to paste a column from Excel.
How to Convert Erg to Joule
- 1 erg = 1 × 10⁻⁷ J
- 1 J = 10000000 erg
- Example: convert 15 erg to J: 15 erg = 15 × 1 × 10⁻⁷ J = 0.0000015 J
Formula
J = erg ÷ 10000000
Derivation from SI units:
- 1 erg = 1 dyn·cm = 10⁻⁷ J
- 1 J = 1 N·m = 1 W·s = 1 kg·m²·s⁻²
Both units are defined exactly, so the factor is exact. Erg definition: erg; Joule definition: joule.
Worked examples
- A reading of 1000 erg converts to 0.0001 J.
1000 erg × 1 × 10⁻⁷ = 0.0001 J - A value of 1e6 erg is 0.1 J.
1e6 erg × 1 × 10⁻⁷ = 0.1 J
Erg to Joule conversion table
| Ergs (erg) | Joules (J) |
|---|---|
| 1 erg | 1 × 10⁻⁷ J |
| 10 erg | 0.000001 J |
| 100 erg | 0.00001 J |
| 1000 erg | 0.0001 J |
| 10000 erg | 0.001 J |
| 1e5 erg | 0.01 J |
| 1e6 erg | 0.1 J |
| 1e7 erg | 1 J |
| 1e10 erg | 1000 J |
| 3.828e33 erg | 3.828 × 10²⁶ J |
Where it's used
Ergs are used for astrophysics (luminosities in erg/s), while joules appear in physics and engineering energy balances. Both measure energy, work and heat, so the conversion is a fixed factor.
Erg to other energy units
| Conversion | 1 erg equals |
|---|---|
| erg to joule | 1 × 10⁻⁷ J |
| erg to kilojoule | 1 × 10⁻¹⁰ kJ |
| erg to megajoule | 1 × 10⁻¹³ MJ |
| erg to calorie | 2.390057361 × 10⁻⁸ cal |
| erg to kilocalorie | 2.390057361 × 10⁻¹¹ kcal |
| erg to watt-hour | 2.777777778 × 10⁻¹¹ Wh |
| erg to kilowatt-hour | 2.777777778 × 10⁻¹⁴ kWh |
| erg to BTU | 9.478171203 × 10⁻¹¹ BTU |
| erg to therm | 9.48043428 × 10⁻¹⁶ thm |
| erg to electronvolt | 624150907400 eV |
| erg to foot-pound | 7.375621493 × 10⁻⁸ ft·lbf |
Frequently asked questions
How many joules are in 1 erg?
1 erg = 1 × 10⁻⁷ J.
How do I convert ergs to joules?
Multiply the value in erg by 1 × 10⁻⁷, or divide it by 10000000. For example, 15 erg × 1 × 10⁻⁷ = 0.0000015 J.
Is the erg to J conversion exact?
Yes. Both units are defined exactly, and 1 erg is exactly 1 × 10⁻⁷ J.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "erg (erg)".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Ergs to Joules. Retrieved October 17, 2026, from https://scientificconverters.com/energy/ergs-to-joules/
IEEE
Scientific Converters, "Convert Ergs to Joules," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/ergs-to-joules/