Most of prefab countertops are sized by 96" x 26"x3/4" or 108" x 25 1/2"x1 1/4", islands are by size 72" x 36" or 72" x 39" or free length x 42". Standard width for bar tops is 18". Standard back splashes are 4", 6" or 18" full height. Standard width of bathroom vanity top is either 19" or 22", some people use 22 1/2". The length can be 25", 31", 37", 49", or 61". Sink clips help put under mount porcelain sinks. Other bathroom products are stone shower pans, trays, shower bases, tub decks, 3/8" tub surrounds and shower surrounds, shower which are mostly in size 60"x30" or 72"x30".