Cal. King Comforter in a King size duvet???

I am having a hard time finding a cal. king duvet for our cal. king down comforter. I was wondering if it would fit in a king size duvet if it was smooshed inside. I think cal. king is only a little bit longer than regular king.
Anybody try this? I've been looking all over the internet for affordable ones, and i'm having no luck. There's not much of a selection out there.
Thanks.

Cal king are longer...but also narrower...so I don't think it would work too well...


have you checked online...like macys...overstock...even like QVC?