 The free throw circle has a six @-@ foot ( 1 @.@ 8 m ) radius and is centered at the midpoint of the free throw line ; the half of those circle on the mid @-@ court side of the free throw line is painted in solid lines . In the NBA and <unk> , the boundaries of the half closer to the basket is traced in a broken line in order to space players properly for jump balls . NBA Rule 1 ( g ) requires the key to contain two 6 inches ( 15 cm ) long <unk> marks , 3 feet ( 0 @.@ 91 m ) from the free throw line ; the marks indicate the so @-@ called lower defensive box . The free @-@ throw line is 15 feet ( 4 @.@ 6 m ) from the perpendicular projection of the face of the <unk> onto the court ; this projection is 4 feet ( 1 @.@ 2 m ) from the end @-@ line for NBA and NCAA . The projection of the center of the basket onto the court is a perpendicular distance of 1 @.@ 575 meters ( 5 @.@ 17 ft ) from the end line in FIBA tournaments , but 4 @.@ 75 feet ( 1 @.@ 45 m ) in NBA and NCAA tournaments . 
