What is the SI unit of electric charge?

The SI unit of electric charge is the coulomb, symbol C. It measures the quantity of electric charge and is named after French physicist Charles-Augustin de Coulomb, whose work helped establish the mathematical description of electric forces.

A coulomb can be understood through current: one coulomb is the amount of charge transferred by a current of one ampere flowing for one second. This relationship is written Q=It, where Q is charge, I is current, and t is time. The coulomb is therefore an SI derived unit rather than one of the seven SI base units.

The coulomb is much larger than the charge carried by a single electron or proton. One coulomb corresponds to approximately 6.24×10¹⁸ elementary charges. An electron carries a charge of −e, while a proton carries +e.

The distractors represent different electrical quantities. The volt measures potential difference, the farad measures capacitance, and the ampere measures electric current. They are related to charge but are not its SI unit.