SI Units
| Dimension | mass (M) | length (L) | time (T) | Charge(Q) |
| SI Unit | kilogram (kg) | meter (m) | second (s) | Coulomb (C) |
| Atomic units | me=9.11-31 kg | a0=5.291-11 m | t0=2.42-17 s | e =1.602-19 C |
| Derived units | Energy | Momentum | Force | Pressure |
| Dimension | ML2T-2 | MLT-1 | MLT-2 | M-1LT-2 |
| SI Unit | Joule (J) | Newton (N) | Pascal (Pa=N/m2) |