Height
The proper height for a dartboard is 5 feet, 8 inches, measured from the floor to the center of the inner bull's-eye. Variations of game play do not alter the height.
Distance in Regulation Play
The throwing line behind which players stand, called the "oche," is 7 feet, 9.25 inches from the face of the board.
Distance in Casual Games and Pubs
Occasionally in British pubs, the oche is placed at 8 feet or 8 feet, 6 inches. Some rule sheets for casual home play, meanwhile, suggest drawing the line at 7 feet, 6 inches or 8 feet. None of these is acceptable for regulation play, according to the WDF.
The Oche Itself
You'll often find that the oche itself is a piece of wood that stands an inch or two off the floor. This is to prevent arguments in the event that a player steps over the line when throwing.
Fun Fact
Though most darts are roughly 5 to 6 inches long, the maximum allowable length for a regulation dart is a seemingly awkward 12 inches.