A standard round crib has a mattress that is 42 inches in diameter. The frame usually measures a total of between 44 and 50 inches in diameter, depending on the style.
Because a standard rectangular crib mattress is 10 inches longer than a standard round crib mattress, toddlers will outgrow a round crib sooner than they would outgrow a rectangular crib. The Baby Department states that a 42-inch diameter round crib will accommodate a child until he is about 35 inches tall, usually around 2 1/2 years.
Round cribs are designed to be placed in the center of a room. This leaves more wall space for other furniture, in addition to giving babies the ability to see the room out of all sides of the crib.
Many styles of standard round cribs include a removable canopy, which can provide a whimsical touch to the nursery design.
Because round cribs are specialty items, they can be more expensive than traditional rectangular cribs. As of 2009, a round crib frame and mattress costs $350 or more. In addition, bedding sets are more expensive as well and typically must be ordered online.