The width on mine is 21" from side seem to side seem. It's 11" (not including the handles..which are 13" wide, by 4" tall). So total height is 15". It has a rectangular base with dimensions of 16" length (across..left to right) and a depth of 6". It has 3 inside pockets about 6" deep.
It's pretty roomy. I have my 2 sm. projects inside. A pattern bk., magazine. I have all the notions I need in the 3 pockets and yet there's still room. The ball of yarn I have in there is a 200 yd ball, and also a wound ball(for my socks). I could fit 2 more balls of the 200yd worsted inside but that's packed to the top..(a bit crowdy...but does fit, bag still closes.)
If I wanted to do say a sweater and a sock I think that would fit pretty good...but with not too much extra room(you know like a front or back piece, sleeve). Just to give you an idea. Right now I have a sock project in there...and just started my 2nd project yesterday..(an afghan, done square by square). Btw...14" straights fit very comfortably. I had planned on using these for my afghan..but decided to go with my Denises.
Ck. the dimensions she has listed for each individual bag cuz they seem to vary by an 1" or so. Go to the create your own bag section and it gives you the basic sizes of all her bags.
But like I said where you go to buy...ck the sizes...some will be a bit smaller...some a lil bigger.
Hope this helps!
OTN: Socks, afghan