Anyone swapped an 18.5-inch RV toilet into a tight wet bath?

[elfredaseward]

We have a 2019 Winnebago Class C with a very small wet bath, and the stock toilet is on borrowed time. I keep seeing 18.5-inch RV toilets mentioned as a common size, but I'm not sure it's common in the way that actually helps me. Our current unit sits close to the shower curtain, and the height matters too since I'm 5'7" and don't want my knees jammed into the wall.

What I'd really like to know is whether people have gone from a smaller two-piece plastic toilet to an 18.5-inch one in a compact bathroom, and whether the footprint difference was noticeable in daily use. I'm also uncertain about the flange and water hookup alignment, since I've read that a few inches can mean redoing the supply line. The measurements I've found online don't tell me much about how it feels in a real wet bath.

Anyone here with a similarly sized bathroom who has made this swap? Did the extra height help or make things awkward, and was the install as straightforward as the dimensions suggested?

 

[PolarisCobra]

The thing to pay attention to is the distance from the center of the flange to the wall. If you look at the specs on the toilet company website, you should find a specification of the distance required from the center of the toilet hole to the wall behind it. If that distance is too long, the toilet will hit the wall, and you won't be able to bolt it down.

 

[michaelbrown]

The flange-to-wall distance point is the one I'd check first on our rig. We have a 2017 Winnebago View with the same cramped wet bath, and I'm weighing an 18.5-inch replacement against just rebuilding the plastic two-piece that's in there now. My worry is the supply line: the current hookup comes in from the side low down, and I can't tell from the specs whether a taller bowl leaves enough room to reroute it without pulling the surround. I came across Best RV Toilets of 2026 while comparing sizes, but real-world fit in a wet bath still feels like guesswork. Has anyone with this layout run into the water line being the sticking point?