Common installation styles for 18-inch bathroom sinks include wall-mount (including compact vessel/wall-mount options), countertop/above-counter (vessel), undermount, and semi-recessed configurations.
Measured as overall height, depths in the data typically range from about 4.3 inches up to about 5.1 inches.
Typical drain dimensions shown include a drain cap diameter of 2 3/8" and a tailpiece outer diameter of 1 1/4"; another countertop basin lists a drain hole diameter of about 1.8".
Weights vary across examples, roughly 16.5 to 40.0 pounds. Several sink and basin options cluster near 19–21 pounds, with some heavier entries listed up to about 40 pounds.
Most offerings shown are rectangular sinks and basins around 18.1". The category also includes square, round, and oval shapes and multiple mounting styles (countertop, undermount, semi-recessed).