Question regarding carry-on bag size requirements

I'll be going on my first ever flight with United in a couple months, just a nonstop 2.5hr flight within the US, but I'm having trouble finding a carry-on bag that fits the exact size requirements! I am trying to find a 22 x 14 x 9 in hardside rolling luggage like United's website states, but everything I see seems to be slightly over that, like an inch or half an inch, in at least one of the dimensions. I almost bought one today at TJMaxx but it was 22 x 14 x 9.5 in. Is that an acceptable size? If not, can someone tell me where to find a hardside rolling luggage that is exactly 22 x 14 x 9 in? I still need to find a personal bag as well, but that comes next lol.