Index

## DEFININGCONSTANTSYMBOL: h

**PID**: si:definingconstantsymbol:h:2019**Definition**: The Planck constant,*h*, is exactly 6.626 070 15 × 10^{-34}J s.**Source**:*SI Brochure 9th Ed. 2019, p 127***Formatted**:`6.626 070 15 x 10`

^{-34}J s**Numerical Value**:*6.62607015E-34***Unit**: J s**Unit in Base SI**: kg m^{2}s^{-1}**Notes**- This value was fixed by the CGPM in 2018 (Resolution 1), with effect from 20 May 2019.
- The Planck constant is a fundamental constant that determines quantum effects and affects all particles and fields equally on all scales and in all environments.

**Representations**- Text:
`h`

- HTML:
`<em>h</em>`

- Latex:
`h`

- Text:
**Related Definitions**- isConstantSymbolOf -> Planck constant