In the field of electromagnetism, in addition to the standard International System of Units (SI), CGS Gaussian units are also frequently employed. For those working with magnetic materials, this often necessitates unit conversions—a process that can be computationally complex given the intricate relationships between these two systems.
To facilitate ease of use for everyone, we have systematically compiled a summary of electromagnetic units and the conversion relationships between the various unit systems. We encourage you to bookmark this resource for future reference.
**The International System (SI) vs. The Gaussian System (CGS)**
Within the International System of Units (SI), the specific framework for electromagnetism is the rationalized MKSA system. The MKSA system defines the units for four fundamental physical quantities in electromagnetism: length, mass, time, and electric current. These are designated as the meter (m), kilogram (kg), second (s), and ampere (A), respectively.
The Gaussian system of units was established by building upon two earlier frameworks: the absolute electrostatic system (CGSE or e.s.u.) and the absolute electromagnetic system (CGSM or e.m.u.). Simply put, the Gaussian system serves as a unified synthesis of these two predecessors, creating a comprehensive system of electromagnetic units that is also referred to as a "mixed unit system." The absolute electrostatic system selects length, mass, and time as its three fundamental quantities, with their corresponding units being the centimeter (cm), gram (g), and second (s).
**Conversion Relationships Between the SI and CGS Systems**
To convert a value from the SI system to the CGS system, one simply needs to multiply the SI value by the corresponding conversion ratio. Given the complexity of these conversion relationships, we will not detail the specific derivation processes here.
