Title: ampere
Long Title: IUPAC Gold Book - ampere
DOI: 10.1351/goldbook.A00300
Status: current
Index: unit

Definition
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 \(1.602\ 176\ 634\times10^{-19}\) when expressed in the unit \(\rm{C}\), which is equal to \(\rm{A s}\), where the second is defined in terms of ΔνCs.

Related Terms
- elementary charge: https://goldbook.iupac.org/terms/view/E02032
- Δ<em>ν</em><sub>Cs</sub>: https://goldbook.iupac.org/terms/view/S05854

Source
- BIPM, The International System of Units, SI Brochure, 9th ed. (2019), p. 132 (https://www.bipm.org/en/publications/si-brochure/)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/A00300/html
- json: https://goldbook.iupac.org/terms/view/A00300/json
- xml: https://goldbook.iupac.org/terms/view/A00300/xml

Citation: Citation: 'ampere' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.A00300
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Accessed: 2026-08-10T14:04:33+00:00