10-Inch vs 12-Inch Rough-In: How to Measure Before You Buy a Smart Toilet

The rough-in is the one measurement that decides whether a toilet fits your bathroom. Getting it right takes a tape measure and one minute.

What is the rough-in?

It is the distance from the finished wall behind the toilet to the center of the drain in the floor. Most homes in the United States have a 12-inch rough-in. Some older homes and small bathrooms have 10 inches.

Smart toilet in a small bathroom, showing the space to the back wall and in front of the bowl — Check both: the distance to the back wall and the room in front of the bowl.

How to measure it

Find the two bolts that hold your current toilet to the floor. They sit in line with the center of the drain.
Measure from the wall behind the toilet to the center of one bolt. Measure from the wall itself, not from the baseboard.
If you get about 12 inches, you have a 12-inch rough-in. About 10 inches means a 10-inch rough-in.

If your number is around 14 inches, or the toilet has no bolts you can see, text us a photo and we will tell you what fits.

Which smart toilets fit each size?

Every model in our catalog fits a 12-inch rough-in. For 10 inches, the DeerValley 0029 and 0019 come in a 10-inch version of their Advanced level. Choose the 10-inch rough-in option on the model page.

What about the space in front of the toilet?

Smart toilets are long. The models we carry measure about 26 to 27.5 inches from the back to the front of the bowl. Measure from the wall to the door, vanity or tub in front of the toilet and make sure you still have room to stand and sit comfortably.

Not sure? We check it for you

If you choose an installed smart toilet, we confirm the rough-in before we order, so you never get a toilet that does not fit.

Find a smart toilet that fits your bathroom →