In microfluidics, dead volume refers to the space in a system where fluid stagnates and is not actively transported or utilized, often leading to inefficiencies or contamination. Swept volume, on the other hand, is the actively utilized volume through which fluid flows during operation, critical for ensuring efficient reagent usage and process reliability. Void volume generally denotes the empty space within a system or between packed materials, such as in a column, that can affect fluid flow and system dynamics.

The liquid volume inside a tube (with a circular cross-section) is determined by the volume of the cylinder formed by the tube's internal diameter (ID) and its length.