What indoor flood lights fit in my 6" recessed can?

A 6" in diameter recessed can is a common size of can in overall room lighting. You can either use an incandescent BR40 in this size can or a PAR38. A BR40 light bulb is 5" in diameter and the PAR38 light bulb is 4 3/4" in diameter. You want to choose a light bulb that is roughly an inch smaller than the size of your can. Much tighter and it may be difficult for you to screw in and unscrew the bulb.