 Goals consist of two upright posts placed equidistant from the centre of the backline , joined at the top by a horizontal crossbar . The inner edges of the posts must be 3 @.@ 66 metres ( 4 yd ) apart , and the lower edge of the crossbar must be 2 @.@ 14 metres ( 7 ft ) above the ground . The goalposts and crossbar must be white and rectangular in shape with width 50 millimetres ( 2 in ) and a depth of 50 to 75 millimetres ( 2 to 3 in ) . A backboard of height 460 millimetres ( 18 in ) extends for the width of the goal and a sideboard of the same height must extend for at least 1 @.@ 20 m ; the goal must be at least this deep at ground level and at least 0 @.@ 90 m deep at crossbar level . <unk> to these boards , the posts and crossbar is a net to stop the ball . 
