Meterkilogramsecondampere

Meterkilogramsecondampere is the product of four SI base units: metre (m), kilogram (kg), second (s), and ampere (A). It is not a standard SI unit nor a named unit; rather, it is a composite unit used primarily in dimensional analysis or as a placeholder symbol in equations to indicate a quantity with dimensions of length, mass, time, and electric current combined.

In SI base units, its dimension is M L T I, commonly written as kg·m·s·A. This reflects a quantity that changes with mass, length, time, and current, but it has no widely recognized physical interpretation or common usage. There is no widely used symbol beyond the factorization into m, kg, s, and A.

Practical usage is limited: scientists typically convert to more conventional derived units when possible, such as newton (kg·m·s^-2), joule (kg·m^2·s^-2), or coulomb (A·s), depending on the context. Without a context, the product does not represent a standard physical quantity.

Because it lacks an established meaning, the term is mainly of interest in discussions of dimensional analysis, unit algebra, or teaching examples illustrating how SI base units combine.

See also: International System of Units, SI base units, Dimensional analysis, Derived units, Metre, Kilogram, Second, Ampere.