More a of material question then a pattern one

im making a hat on circular needles and it says “Needle, circular (size 15, 16” long)" so that means they should be 16 inches in circumference? so I cant use size 15 needles that at 29 inches, right?

no…the work won’t stretch around a 29inch circ (unless you are knitting flat of course)

16 is a good size to have because it is perfect for almost all hats.