This question is in two parts. I was going to start knitting a hat but the pattern calls for 24"circular needles (Knitpick Chemo Hat).

1) How do I determine the length of circular needles? I have many but most of them where purchased in Korea and don't come in packages with such information on them.

2) Does this have be done on circulars? Can it not be done on DPN?

Thanks!

circs are measured tip to tip, they can be as much as an inch off standard lengths. You can probably use a shorter circ w/out any problems.

And yes, you can also use double pointed needles.

There are a few other methods for knitting small diameters - magic loop and the 2 circ method. There is a ML video right here, not sure if there is one here for 2 circs. Additional info on both can be found by googling.