Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 kJ | 1e+07 erg | |
| 0.01 kJ | 1e+08 erg | |
| 0.1 kJ | 1e+09 erg | |
| 1 kJ | 1e+10 erg | |
| 5 kJ | 5e+10 erg | |
| 10 kJ | 1e+11 erg | |
| 50 kJ | 5e+11 erg | |
| 100 kJ | 1e+12 erg | |
| 1000 kJ | 1e+13 erg |
Formula: Erg = Kilojoule × 1e+10
Multiply any kilojoule value by 1e+10 to get erg.
Reverse: Kilojoule = Erg × 1.0000e-10
Common kilojoule values — factor: 1 kJ = 1e+10 erg
| Kilojoule (kJ) | Erg (erg) | Context |
|---|---|---|
| 0.001 kJ | 1e+07 erg | 1 J |
| 0.01 kJ | 1e+08 erg | 10 J |
| 0.1 kJ | 1.000e+09 erg | 100 J |
| 1 kJ | 1.000e+10 erg | 1 kJ |
| 4.184 kJ | 4.184e+10 erg | 1 kcal |
| 10 kJ | 1.000e+11 erg | 10 kJ |
| 100 kJ | 1.000e+12 erg | 100 kJ |
| 1,000 kJ | 1.000e+13 erg | 1 MJ |
| 3,600 kJ | 3.600e+13 erg | 1 kWh |
| 1e+04 kJ | 1.000e+14 erg | 10 MJ |
| 1e+05 kJ | 1.000e+15 erg | 100 MJ |
| 1e+06 kJ | 1.000e+16 erg | 1 GJ |
| 1e+08 kJ | 1.000e+18 erg | 100 GJ |
| 1.000e+10 kJ | 1.000e+20 erg | 10 TJ |
| 1.000e+12 kJ | 1.000e+22 erg | 1 PJ |
1 kJ = 1e+10 erg. Memorize for instant estimates.
Use 1e+10 as a quick mental multiplier.
Multiply result by 1.0000e-10 to recover the original kJ value.
Labels food energy in kJ for metric-market nutritional information.
Calculates reaction heat, enthalpy changes, and process energy in kJ.
Measures athlete metabolic rate and substrate oxidation in kJ.
Teaches heat transfer, steam tables, and engine cycles using kJ.
Prescribes energy intake using kJ in countries using metric labels.
Calculates heat duty for reactors, heat exchangers, and distillation in kJ.
The kilojoule (kJ) equals 1,000 joules and is the practical energy unit for food, chemistry, and heating applications in metric countries. Food energy labels in Australia, Europe, and most of the world use kilojoules.
A dietary calorie (kcal) equals 4.184 kJ. A can of soda contains about 600 kJ. The specific heat of water (4.184 kJ/kg·°C) means heating 1 liter of water by 1°C requires 4.184 kJ.
Interesting fact: An average adult needs about 8,000-10,000 kJ (2,000-2,400 kcal) per day. Running a marathon burns approximately 12,500 kJ.
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 kilojoule 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 kJ = 5e+10 erg and 10 kJ = 1e+11 erg. Reverse: 1 erg = 1.0000e-10 kJ. Exact factor: 1 kJ = 1e+10 erg.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.