To prevent splash-over, a jetted tub should have an apron taller than the 14-inch standard. The Cadet Integral Apron Whirlpool by American Standard measures 19 3/4 inches high.
American Standard's Minette lav is 11x16 3/4 inches
Standard vanities are 18 to 21 inches deep, 24 inches wide, and 30 to 38 inches tall. The Strasser Eurolav, with integral sink top, measures only 26½x13½ inches.
Compass by Kohler is 13½ inches in diameter.
Standard tubs are 5 feet long. Standard showers are 36 inches square and at least 32 inches wide. Shown here is the Versailles by Maax, which is 29 5/8 x 31 3/4 x 74 3/4 inches.
Standard elongated toilets are 29 to 31 inches deep. The Compact Elongated Space Saver by American Standard measures only 27½x19 inches.
Kohler's rounded front Rialto is 25½ inches front to back.
The Biarritz 40 shower from Maax measure 38½ in. sq.
Small-scale fixtures can save you lots of grief when you need to save an inch or two in a compact bathroom. Keep code-mandated distances between fixtures and door clearances in mind. Switching the hinges can solve a problem swing; a pocket door is helpful in tight situations. On shower enclosures, bypass or bifold doors conserve space.