Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 J | 10000 erg | |
| 0.01 J | 100000 erg | |
| 0.1 J | 1e+06 erg | |
| 1 J | 1e+07 erg | |
| 5 J | 5e+07 erg | |
| 10 J | 1e+08 erg | |
| 50 J | 5e+08 erg | |
| 100 J | 1e+09 erg | |
| 1000 J | 1e+10 erg |
Formula: Erg = Joule × 1e+07
Multiply any joule value by 1e+07 to get erg.
Reverse: Joule = Erg × 1.0000e-7
Common joule values — factor: 1 J = 1e+07 erg
| Joule (J) | Erg (erg) | Context |
|---|---|---|
| 0.001 J | 1e+04 erg | 1 mJ |
| 0.1 J | 1e+06 erg | Heartbeat |
| 1 J | 1e+07 erg | Lift apple 10cm |
| 4.184 J | 4.184e+07 erg | 1 calorie |
| 100 J | 1.000e+09 erg | Sprinting 1 sec |
| 1,000 J | 1.000e+10 erg | 1 kJ |
| 4,184 J | 4.184e+10 erg | 1 kcal food |
| 1e+04 J | 1.000e+11 erg | 10 kJ |
| 1e+05 J | 1.000e+12 erg | 100 kJ |
| 1.055e+06 J | 1.055e+13 erg | 1 BTU |
| 3.6e+06 J | 3.600e+13 erg | 1 kWh |
| 1e+08 J | 1.000e+15 erg | ~100 MJ |
| 1.000e+09 J | 1.000e+16 erg | 1 GJ |
| 1.000e+12 J | 1.000e+19 erg | 1 TJ |
| 1.000e+15 J | 1.000e+22 erg | 1 PJ |
1 J = 1e+07 erg. Memorize for instant estimates.
Use 1e+07 as a quick mental multiplier.
Multiply result by 1.0000e-7 to recover the original J value.
Uses joules as the SI unit for all energy, work, and heat calculations.
Calculates kinetic energy, potential energy, and work in joules.
Measures reaction enthalpies, bond energies, and heat of solution in joules.
Converts between power (watts) and energy (joules = watt-seconds).
Measures fracture energy and impact resistance in joules.
Applies the first law of thermodynamics with energy in joules.
The joule is the SI derived unit of energy, work, and heat, defined as the energy transferred when a force of one newton moves an object one meter. It was named after James Prescott Joule, the English physicist who established the mechanical equivalent of heat in the 1840s.
The joule is universal in physics and engineering: kinetic energy (½mv²), potential energy (mgh), electrical energy (VIt), and heat are all measured in joules. One joule is the energy needed to lift a 100g apple one meter against gravity.
Interesting fact: The human heart expends about 1 joule of energy with each beat. A 60-watt light bulb uses 60 joules every second. The entire energy released by a 1-megaton nuclear weapon equals about 4.18 × 10¹⁵ joules.
The erg is the unit of energy in the CGS (centimeter-gram-second) system, equal to exactly 10⁻⁷ joules. It was defined by the British Association for the Advancement of Science in 1882 as the work done by a force of one dyne over one centimeter.
Ergs were widely used in 19th and early 20th century physics before SI standardization. They remain in use in astrophysics (stellar luminosities in erg/s) and some older scientific literature.
Interesting fact: The Sun radiates about 3.8 × 10³³ ergs per second. A mosquito in flight exerts about 100 ergs of energy per wingbeat. One joule = 10,000,000 ergs exactly.
Converting joule to erg is common across energy, nutrition, engineering, and science. Different sectors use different energy units — joules in physics, kcal in nutrition, kWh in electricity, and BTU in HVAC — making accurate conversion essential for cross-disciplinary work and international comparisons.
Quick reference: 5 J = 5e+07 erg and 10 J = 1e+08 erg. Reverse: 1 erg = 1.0000e-7 J. Exact factor: 1 J = 1e+07 erg.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.