A standard kit of full length strips for most kayaks is about 65 pieces. If you figure you lose one strip to sawdust for every two you cut that means you need 65+22 times ¼" = enough boards to equal about 22", or a bit more, combined width that are a bit longer than the finished hull.
I use this system because I can walk up to a pile of boards, take the ones I prefer and lay them on the floor shoulder to shoulder till I have a raft that is at least 22" wide and 18' long and I should have enough.

: Hey all,

: I'm buying cedar boards for a Fire Star baidarka, and I'm wondering
: how I calculate how much wood to get. I may need to drive a
: couple hours to pick it up, so I'd greatly prefer to make one
: trip.

: I'll be sticking with 8-10' boards if it matters.

: Thanks!