I'm extremely frustrated about sizing for duvets. I tried the King size with my Cal-King duvet cover (accidentally had ordered K instead of Cal-K). Neither direction worked for me. Okay, that makes sense. But once I realized my mistake I returned it and got the Cal King. But fck me.... NEITHER DIRECTION WORKS for the Cal King either! There is so much empty space on some sides and it's too short/bunched on the other side. I honestly don't understand how this is supposed to work.
I have ordered Queen duvets for Queen duvet covers, and and K for Cal K and Cal K for Cal K.... NOTHING ever seems to fit correctly.