My oldest son's head is about 21.5 inches in diameter, my baby's is about 15.5 inches, didn't measure the other daughter & son in between.
Think a 16 incher would work? Is that a standard size? They are measured tip to tip, right? I know I could use DPNs and would probably have to, to finish up at the top, but I might as well add some shorter circs to my inventory, especially since the interchangeable kits seem to have longer cords.
I'm waiting for Hobby Lobby to get in their Needlemaster sets since they are sold out (and got a rain check for the half-off price!), but the in-laws also got me a gift certificate for by birthday that is burning a hole in my pocket for a small local craft store that has yarn and some knitting supplies .