As you'll be working with a small bathroom, there are certain variables that you must consider in terms of the dimensions of a sink.
Width - The width of a basin is measured starting from the back of a bowl up to its front portion. It is important that you get the measurements of your space before you start the buying process.
Length - You also need the appropriate length for your pedestal sink. It is measured from one side to the other inside the bowl.
The height, width, and depth of a pedestal sink should fit your bathroom's layout. Modern basins are typically 60-90 cm wide with 70-120 cm for the integrated units.