The ampere, symbol \(\text{A}\), 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 × 10
-19 when expressed in the unit C, which is equal to A s, where the second is defined in terms of Δ
νCs.
Source:
BIPM, The International System of Units, SI Brochure, 9th ed. (2019), p. 132 (https://www.bipm.org/en/publications/si-brochure/)