Constants & Units · constant

Elementary charge

e = 1.602 176 634 × 10⁻¹⁹ C

Unit

C

Value

1.602 176 634 × 10⁻¹⁹

Exact

yes

Note

Fixes the ampere. The charge of a proton; quarks carry thirds of it.

Symbol

e

Category

Defining (SI)

Numeric

1.602176634e-19

Uncertainty

exact

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From the Constants database in Notion, last edited 2026-08-15. This page is the row, rendered by the build; nothing on it is written by hand.