The ampere (symbol A) is the SI base unit of electric current, per the BIPM SI Reference Point.
- Name: ampere
- Symbol: A
- Unit type: SI base unit
- Quantity kind: electric current
- Definition (status current, in force since 2019-05-20): The ampere, symbol $\rm{A}$, is the SI unit of electric current. It is defined by taking the fixed numerical value of the elementary charge, ${e}$, to be ${1.602\:176\:634 \times 10^{-19}}$ when expressed in the unit $\rm{C}$, which is equal to ${\rm{A}}\ {\rm{s}}$, where the second is defined in terms of $\Delta\nu_{\rm{Cs}}$.
- Defining constant: elementary charge (fixed numerical value 1.602 176 634 x 10⁻¹⁹)
- Defining equation: 1\;{\rm{A}} = \left(\frac{{e}}{{1.602\:176\:634 \times 10^{-19}}}\right) {\rm{s}}^{-1}
- Defining resolution: https://si-digital-framework.org/bodies/CGPM#CGPM26-Res1
- Superseded definitions: ampere1948 (1948-01-01 to 2019-05-19)