On sinks (lavs),
1 - a single hole

4- the outer holes are set at 4" center to center.
A total of three holes.

8- the outer holes are set at 8" center to center. ( Also called "wide spread" )
A total of three holes.

: I have been looking at the Kohler line of Pedestal sinks and they come in 1", 4", and 8" centers ? I hate to admit this but I dont understand what the 1",4",8" center is
measuring ?