Erg to Joule Converter
Enter the value that you want to convert erg to joule (J) or joule to erg.
1 erg = 0.0000001 joule
Formula: joule = erg value × 0.0000001
erg to joule
10 erg = 0.00000 joule
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Erg to Joule: The Essentials
The Erg in Engineering
Erg (erg) is a unit of energy measurement. 1 erg is equal to 0.0000001 joule.
The Joule in Engineering
Joule (J) is a unit of energy measurement. 1 joule is equal to 10000000.0000000 erg.
Energy Units in Different Fields
Energy measurement units reflect their historical origins across different industries. Electrical engineers use kilowatt-hours, nutritionists use calories, physicists use joules, heating engineers use BTUs, and the petroleum industry uses barrels of oil equivalent. Converting between these units is essential for energy auditing, comparing fuel sources, sizing HVAC systems, and understanding electricity bills relative to gas consumption.
erg to joule metric conversion table
| 0.01 erg | = | 0.00000 J |
| 0.1 erg | = | 0.00000 J |
| 1 erg | = | 0.00000 J |
| 2 erg | = | 0.00000 J |
| 3 erg | = | 0.00000 J |
| 4 erg | = | 0.00000 J |
| 5 erg | = | 0.00000 J |
| 6 erg | = | 0.00000 J |
| 7 erg | = | 0.00000 J |
| 8 erg | = | 0.00000 J |
| 9 erg | = | 0.00000 J |
| 10 erg | = | 0.00000 J |
| 11 erg | = | 0.00000 J |
| 12 erg | = | 0.00000 J |
| 13 erg | = | 0.00000 J |
| 14 erg | = | 0.00000 J |
| 15 erg | = | 0.00000 J |
| 16 erg | = | 0.00000 J |
| 17 erg | = | 0.00000 J |
| 18 erg | = | 0.00000 J |
| 19 erg | = | 0.00000 J |
| 20 erg | = | 0.00000 J |
| 30 erg | = | 0.00000 J |
| 40 erg | = | 0.00000 J |
| 50 erg | = | 0.00000 J |
| 60 erg | = | 0.00001 J |
| 70 erg | = | 0.00001 J |
| 80 erg | = | 0.00001 J |
| 90 erg | = | 0.00001 J |
| 100 erg | = | 0.00001 J |
| 200 erg | = | 0.00002 J |
| 300 erg | = | 0.00003 J |
| 400 erg | = | 0.00004 J |
| 500 erg | = | 0.00005 J |
| 600 erg | = | 0.00006 J |
| 700 erg | = | 0.00007 J |
| 800 erg | = | 0.00008 J |
| 900 erg | = | 0.00009 J |
| 1000 erg | = | 0.00010 J |
How to Convert Erg to Joule?
We can convert erg to joule by using an example.
Example:
Convert 20 Erg to Joule?
We know 1 Erg = 0.0000001 joule; 1 Joule = 10000000.0000000 erg.
20 erg = ___J
20 × 0.0000001 = 0.00000 J (we know 1 erg = 0.0000001 joule)
Answer:
20 erg = 0.00000 joule
How to Convert Ergs to Joules (Step-by-Step)
The erg is the energy unit in the CGS (centimeter-gram-second) system, still used in some scientific fields. The conversion is exact: 1 erg = 10⁻⁷ J (one ten-millionth of a joule). This means 10 million ergs equal 1 joule.
- Identify the energy value in ergs.
- Multiply by 10⁻⁷ (or divide by 10,000,000) to convert to joules.
- Equivalently, move the decimal point 7 places to the left.
- For large erg values, express the result in standard SI prefixes (mJ, μJ, etc.).
Common Ergs to Joules Conversions
Reference values spanning from microscopic laboratory measurements to astrophysical energy scales.
| Erg | Joule |
|---|---|
| 1 erg | 10⁻⁷ J (0.1 μJ) |
| 10⁷ ergs | 1 J |
| 4.184 × 10⁷ ergs | 4.184 J |
| 10¹⁰ ergs | 1,000 J (1 kJ) |
| 10¹⁵ ergs | 10⁸ J (100 MJ) |
| 10²⁵ ergs | 10¹⁸ J (1 EJ) |
| 10⁴⁴ ergs | 10³⁷ J |
Solved Examples: Ergs to Joules
Question 1: A physics paper reports energy of 5 × 10¹² ergs. Convert to joules.
Solution:
Start with 5 × 10¹² ergs.
Multiply by 10⁻⁷: 5 × 10¹² × 10⁻⁷ = 5 × 10⁵ J.
Express in kJ: 5 × 10⁵ J = 500 kJ.
Answer: 5 × 10¹² ergs = 5 × 10⁵ J = 500 kJ
Question 2: A magnitude 4 earthquake releases about 10¹⁸ ergs. Express in joules.
Solution:
Start with 10¹⁸ ergs.
Multiply by 10⁻⁷: 10¹⁸ × 10⁻⁷ = 10¹¹ J.
Express in GJ: 10¹¹ J = 100 GJ.
Answer: 10¹⁸ ergs = 10¹¹ J = 100 GJ (magnitude 4 earthquake)
Question 3: Convert 3.5 × 10⁸ ergs to joules.
Solution:
Start with 3.5 × 10⁸ ergs.
Multiply by 10⁻⁷: 3.5 × 10⁸ × 10⁻⁷ = 35 J.
Answer: 3.5 × 10⁸ ergs = 35 J
Question 4: A supernova releases approximately 10⁴⁴ ergs. Convert to joules.
Solution:
Start with 10⁴⁴ ergs.
Multiply by 10⁻⁷: 10⁴⁴ × 10⁻⁷ = 10³⁷ J.
This is also written as 10²⁸ GJ or about 3 × 10²⁶ kWh.
Answer: 10⁴⁴ ergs = 10³⁷ J (the "standard candle" of supernovae)
Practice: Ergs to Joules
Try solving these on your own to test your understanding:
- Convert 2 × 10⁹ ergs to joules. (Answer: 200 J)
- A seismic event releases 10²⁰ ergs. Express in GJ. (Answer: 10,000 GJ = 10 TJ)
- Convert 7.5 × 10⁷ ergs to joules. (Answer: 7.5 J)
- A star emits 3.8 × 10³³ ergs per second. Convert to watts. (Answer: 3.8 × 10²⁶ W)
- Convert 10¹⁰ ergs to kJ. (Answer: 1 kJ)
The CGS System and Scientific History
The erg (from Greek "ergon" = work) was the standard energy unit in physics for over a century. The CGS system (centimeter-gram-second), adopted in 1874, used the erg (1 g·cm²/s²) as its energy unit. While SI (MKS) officially replaced CGS in 1960, many scientific fields still use ergs: astrophysics reports stellar luminosity in erg/s, seismology historically measured earthquake energy in ergs, and some spectroscopy papers still use erg/cm²/s for flux density.
Ergs in Seismology: Earthquake Energy
The Gutenberg-Richter energy-magnitude relation gives earthquake energy in ergs: log₁₀(E) = 11.8 + 1.5M, where E is in ergs and M is magnitude. A magnitude 5 earthquake: 10¹⁹·³ ergs ≈ 2 × 10¹² J ≈ 2 TJ. A magnitude 8: 10²³·³ ergs ≈ 2 × 10¹⁶ J ≈ 20 PJ. Each whole magnitude step represents 31.6× more energy. Converting to joules gives more intuitive comparisons (e.g., a magnitude 6 = roughly 1 kiloton TNT).
Astrophysics: Why 10⁴⁴ Ergs Matters
In astrophysics, a "standard" supernova releases about 10⁴⁴ ergs (called a "foe" — ten to the Fifty-One Ergs). This equals 10³⁷ J or about 3 × 10²⁶ kWh — more energy than the Sun will produce in its entire 10-billion-year lifetime. Solar luminosity is 3.8 × 10³³ erg/s = 3.8 × 10²⁶ W. Gamma-ray bursts can reach 10⁴⁷–10⁴⁸ ergs in seconds, making them the most energetic events in the universe.
Key Takeaways
- Multiply ergs by 10⁻⁷ to get joules (exact SI definition).
- 10⁷ ergs = 1 J; 10¹⁰ ergs = 1 kJ.
- The erg is a CGS unit still used in astrophysics and seismology.
- Earthquake energy is traditionally expressed in ergs (Gutenberg-Richter formula).
- A supernova: 10⁴⁴ ergs = 10³⁷ J (called a "foe").
- Solar luminosity: 3.8 × 10³³ erg/s = 3.8 × 10²⁶ W.
Erg to Joule Conversion Formula
joule = erg × 0.0000001
1 erg = 0.0000001 joule
1 joule = 10000000.0000000 erg
Reverse: erg = joule × 10000000.0000000
Frequently Asked Questions
How many joule are in 1 erg?
There are 0.0000001 joule in 1 erg. To convert erg to joule, multiply the value by 0.0000001.
How do I convert erg to joule?
Multiply your erg value by 0.0000001 to get the equivalent in joule. For example, 5 erg = 5 × 0.0000001 = 0.00000 joule.
How do I convert joule to erg?
Multiply your joule value by 10000000.0000000 to get the equivalent in erg. Alternatively, divide by 0.0000001.
What is 10 erg in joule?
10 erg is equal to 0.00000 joule.
What is 100 erg in joule?
100 erg is equal to 0.00001 joule.