# 2019 redefinition of the SI base units

web.archive.org/web/20181119214326/https://www.bipm.org/utils/common/pdf/CGPM-2018/26th-CGPM-Resolutions.pdf gives it in raw:
• the unperturbed ground state hyperfine transition frequency of the caesium-133 atom is 9 192 631 770 Hz
• the speed of light in vacuum c is 299 792 458 m/s
• the Planck constant h is 6.626 070 15 × J s
• the elementary charge e is 1.602 176 634 × C
• the Boltzmann constant k is 1.380 649 × J/K
• the Avogadro constant NA is 6.022 140 76 × mol
• the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, is 683 lm/W,
The breakdown is:
• actually use some physical constant:
• the unperturbed ground state hyperfine transition frequency of the caesium-133 atom is 9 192 631 770 Hz
Defines the second in terms of caesium-133 experiments. The beauty of this definition is that we only have to count an integer number of discrete events, which is what allows us to make things precise.
• the speed of light in vacuum c is 299 792 458 m/s
Defines the meter in terms of speed of light experiments. We already had the second from the previous definition.
• the Planck constant h is 6.626 070 15 × J s
Defines the kilogram in terms of the Planck constant.
• the elementary charge e is 1.602 176 634 × C
Defines the Coulomb in terms of the electron charge.
• arbitrary definitions based on the above just to match historical values as well as possible:
• the Boltzmann constant k is 1.380 649 × J/K
Arbitrarily defines temperature from previously defined energy (J) to match historical values.
• the Avogadro constant NA is 6.022 140 76 × mol
Arbitrarily defines the mol to match historical values. In particular, the kilogram is not an exact multiple of the weight of an atom of hydrogen.
• the luminous efficacy of monochromatic radiation of frequency 540 × 1012 Hz, Kcd, is 683 lm/W
Arbitrarily defines the Candela in terms of previous values to match historical records. The most useless unit comes last as you'd expect.