SI base unit: ampere (A)
The ampere, symbol A, is the SI unit of electric current. It is defined by taking the fixed numerical value of the elementary charge e to be
This definition implies the exact relation e =
![](/documents/20126/42149531/SI-equation-A-1-EN.jpg/01d24ea3-b5b6-cd4c-7751-a48766b7cbf0?t=1594243312426)
which is equal to
![](https://www.bipm.org/documents/20126/42149531/SI-equation-A-2-EN.jpg/5b09bbb1-710e-6356-fecd-3ebbe3e84b09?t=1594243244921)
The effect of this definition is that one ampere is the electric current corresponding to the flow of
See:
SI Brochure - Appendix 2
SI Brochure - excerpts from Appendix 4