Erg Calculator
Convert between different energy units including ergs, joules, and calories
Table of Contents
How to Use
- Enter the energy value you want to convert
- Select the source unit from the dropdown
- Select the target unit you want to convert to
- Click calculate to see the conversion result
- Review the conversion factor and reference information
What is an Erg?
An erg is a unit of energy in the centimeter-gram-second (CGS) system of units. It is defined as the amount of work done by a force of one dyne exerted for a distance of one centimeter.
The erg is a very small unit of energy, equal to 10⁻⁷ joules. While it's not commonly used in everyday measurements, it's still used in some scientific contexts, particularly in physics and astronomy.
Common Energy Units
| Unit | Symbol | Equivalent in Joules | Common Usage |
|---|---|---|---|
| Erg | erg | 1 × 10⁻⁷ J | Physics, astronomy |
| Joule | J | 1 J | SI unit, scientific work |
| Calorie | cal | 4.184 J | Nutrition, chemistry |
| Kilocalorie | kcal | 4,184 J | Food energy |
| Watt-hour | Wh | 3,600 J | Electricity billing |
| Kilowatt-hour | kWh | 3,600,000 J | Household electricity |
| BTU | BTU | 1,055.06 J | Heating/cooling systems |
| Electronvolt | eV | 1.602 × 10⁻¹⁹ J | Atomic physics |
| Foot-pound | ft·lb | 1.356 J | Mechanical work |
Important Conversions
Here are some commonly used energy conversions:
- 1 erg = 1 × 10⁻⁷ joules
- 1 joule = 1 × 10⁷ ergs
- 1 calorie = 4.184 joules
- 1 kilocalorie = 1,000 calories
- 1 watt-hour = 3,600 joules
- 1 kilowatt-hour = 1,000 watt-hours
- 1 BTU = 1,055.06 joules
- 1 electronvolt = 1.602 × 10⁻¹⁹ joules
- 1 foot-pound = 1.356 joules
Applications of Energy Measurements
Different energy units are used in various fields and applications:
- Nutrition: Calories and kilocalories for food energy
- Electricity: Watt-hours and kilowatt-hours for power consumption
- Physics: Joules and ergs for scientific calculations
- Engineering: Foot-pounds for mechanical work
- Chemistry: Calories for heat measurements
- Astronomy: Ergs for stellar energy output
- Particle physics: Electronvolts for subatomic particle energies
Frequently Asked Questions
- What is the relationship between ergs and joules?
- One erg is equal to 1 × 10⁻⁷ joules, and one joule is equal to 1 × 10⁷ ergs. The joule is the SI unit of energy, while the erg belongs to the CGS system.
- Why are there so many different energy units?
- Different energy units evolved historically in different fields and contexts. Some units are more convenient for certain applications - calories for nutrition, watt-hours for electricity, and joules for scientific work.
- How do I convert large energy values efficiently?
- For large values, it's often easier to use kilowatt-hours for electrical energy or kilocalories for food energy. Our calculator automatically formats large numbers with appropriate prefixes (k, M) for better readability.
- What's the difference between a calorie and a kilocalorie?
- One kilocalorie equals 1,000 calories. In nutrition, when people say 'calorie' they usually mean kilocalorie (kcal), which is why food labels use 'Calories' with a capital C to denote kilocalories.
- When should I use ergs versus joules?
- Ergs are typically used in physics and astronomy when dealing with very small energy quantities or when working within the CGS system. Joules are more common in everyday scientific and engineering applications.