CGS System to Electromagnetism
| System |  |  |  |  |  |  |  |  |
|---|---|---|---|---|---|---|---|---|
| Electrostatic CGS (ESU, esu, or stat-) | 1 | c−2 | 1 | c−2 | c−2 | 1 | 4π | 4π |
| Electromagnetic CGS (EMU, emu, or ab-) | c2 | 1 | c−2 | 1 | 1 | 1 | 4π | 4π |
| Gaussian CGS | 1 | c−1 | 1 | 1 | c−2 | c−1 | 4π | 4π |
| Heaviside–Lorentz CGS | 1/4π | 1/4πc | 1 | 1 |  | c−1 | 1 | 1 |
| SI |  |  | | | | 1 | 1 | 1 |