Cells achieve their steady-state size by adding a constant volume between birth and division, regardless of their size at birth. ~ Korean Canadian molecular biologist Suckjoon Jun et al
To realize their biological potential cells must attain a specific size. They do so through certain proteins responsible for growth which are also involved in cell division. The proteins know exactly how large a cell should be by understanding the genetic blueprints. Some eukaryotic cells edit the instructions that these proteins get to alter desired cell size.
It’s a very robust mechanism. ~ Suckjoon Jun