Twin Width: 38" Length: 75" short shaft
Twin XL Width: 38" Length: 80" long shaft
And a super single is 48 x 84 inches. extra long shaft
And full size or double beds are being phased out from what I have heard so bedding will be getting harder to get.
That's bad news. I've been sleeping with my feet hanging over the end for about 52 years now. I have a hard time sleeping on a queen or king. Can't get comfortable. Guess I better stock up on a couple of full size beds in case I last long enough to need them.