Size
Size is the magnitude or dimensions of a thing, or how big something is. Size can be measured as length, width, height, diameter, perimeter, area, volume, or mass.
In mathematical terms, "size is a concept abstracted from the process of measuring by comparing a longer to a shorter". Size is determined by the process of comparing or measuring objects, which results in the determination of the magnitude of a quantity, such as length or mass, relative to a unit of measurement. Such a magnitude is usually expressed as a numerical value of units on a previously established spatial scale, such as meters or inches.