The electrostatic system of units is a system of units used to measure electrical quantities of electric charge, electric current, and voltage within the centimeter-gram-second (or "CGS") system of metric units. In electrostatic units, electrical charge is defined by the force that it exerts on other charges. Although the CGS units have mostly been supplanted by the MKSA (meter-kilogram-second-ampere) or International System of Units (SI) units, the electrostatic units are still in occasional use in some applications, most notably in certain fields of physics such as in particle physics and astrophysics.
The main electrostatic units are:
- The statcoulomb, called the franklin or the "esu" for electric charge.
- The statvolt for voltage.
- The gauss for magnetic induction.