| atomic mass constant (m_u) | 1.660538921 x 10-27 kg |
| Avogadro constant (N_A) | 6.02214129 x 1023 mol-1 |
| Boltzmann constant (k) | 1.3806488 x 10-23 J K-1 |
| electron mass (m_e) | 9.10938291 x 10-31 kg |
| elementary charge (e) | 1.602176565 x 10-19 C |
| Planck constant (h) | 6.62606957 x 10-34 J s |
| Planck constant over 2 pi (\bar h) | 1.054571726 x 10-34 J s |
| electric constant (\epsilon_0) | 8.854187817 x 10-12 F m-1 |
| magnetic constant (\mu_0) | 4pi x 10-7 N A-2 |