How to derive it
Start from a formula that defines electric charge, then replace each quantity with its dimensions. M is mass, L is length, T is time, A is electric current.
- q = current × time = [A] × [T]
- So [electric charge] = [TA], also written [M⁰L⁰T¹A¹].
Dimensional formulas of other quantities
The full searchable list, with SI units, is on the dimensional formula page.
Questions students ask
What is the dimensional formula of electric charge?
[TA] (or [M⁰L⁰T¹A¹]), from q = I t. Its SI unit is coulomb (C) = A s.
What are the dimensions of electric charge?
M: 0, L: 0, T: 1, A: 1.
What is the SI unit of electric charge?
coulomb (C) = A s.