Physical Constants
Quantity | Symbol | Value | Units | |
| electron charge | e | 1.602176634 × 10-19 | C | |
| speed of light | c | 2.99792458 × 108 | m/s | |
| Planck's constant | h | 6.62607015 × 10-34 | J s | |
| reduced Planck's constant |
| 1.054571817 × 10-34 | J s | |
| Boltzmann's constant | kB | 1.380649 × 10-23 | J/K | |
| Gravitational constant | G | 6.67430 × 10-11 | N m2/kg2 | |
| Acceleration of gravity at earth's surface | g | 9.80665 | m/s2 | |
| electron mass | me | 9.1093897 × 10-31 | kg | |
| Stefan-Boltzmann constant | σ | 5.67051 × 10-8 | W m-2 K-4 | |
| Bohr radius | a0 | 5.29177210903 × 10-10 | m | |
| proton mass | mp | 1.67262192369 × 10-27 | kg | |
| neutron mass | mn | 1.67492749804 × 10-27 | kg | |
| atomic mass constant | mu | 1.66053906660 × 10-27 | kg | |
| permeability of vacuum | μ0 | 4π × 10-7 | N A-2 | |
| permittivity of vacuum | ε0 | 8.8541878128 × 10-12 | F m-1 | |
| Coulomb constant | k | 8.987551788 × 109 | m F-1 | |
| Avogado's constant | NA | 6.02214076 × 1023 | mol-1 |
π = 3.1415926535897932384626433832795028841971693993751058209749445...
Fundamental Physical Constants (National Institute of Standards and Technology, USA)SI units
Measurement uncertainty