Standard Dimensions
The standard dimensions of a dartboard is 18 inches in diameter, or nine inches out from the center of the bull's eye.
Standard Board Placement
As long as you are playing a type of dart game that uses the standard board, there is a regulation standard for the board's placement. The bull's eye should be centered at five feet, eight inches off the ground. The throwing line is marked at seven feet and nine and one fourth inches away from the board.
Standard Board Sectioning
Both American and English standard dart games use a board which has 20 radial sections, fanning out from the central bull's eye. Each radial has two rings. The inner ring is worth triple the point score of the radial, and the outer ring is worth double.
"Fives" Board
The "Fives" variant of darts uses the same standard size board (18 inches in diameter), however it is sectioned into twelve equal radials, rather than the standard 20. The points are all multiples of five with five being the lowest, and 20 being the highest. Each number repeats three times on the board.
"Fives" Board Placement
The "Fives" dart board is placed at the same height on the wall as the standard board; however, the throwing line for this board is nine feet from the board.