In general, the toilet rough-in distance is 12″ from the center of the toilet flange to the back wall for a typical toilet. There should also be a minimum of 15″ from the centerline of the toilet to any wall or object on either side of the toilet.

12 inches
Toilet Rough In Dimensions: A toilet’s rough-in measurement is the space between the wall behind the toilet and the center of the waste pipe. Standard toilet rough in dimensions are 12 inches but can be anywhere from 10 to 14 inches in some cases.

15 inches
Most codes require at least 15 inches (measured from the center of the toilet) from any side wall or obstruction and not closer than 30 inches center to center to any other sanitary fixture. (The NKBA actually recommends 32 inches.) There should be at least 24 inches of clear space in front of a toilet or bidet.

Back outlet toilets connect to a plumbing “rough-in” positioned on a bathroom wall rather than on the floor. They use a toilet connection located at the back of the bowl rather than the more common placement of directly below the bowl. All toilets have to connect to a sewer line to dispose of waste.

The toilet rough-in refers to the distance from the finished wall to the center of the toilet’s floor drain or waste outlet. Most toilets have a rough-in of 12 inches, although it’s not uncommon for older homes to have an unusual size such as 10″ or 14″. Rear-outlet toilets are configured a bit differently.

: to make a rough or unfinished version of (something, such as a design) as the first step in creating the finished version Rough in the lettering on your poster.

The rough-in of a rear outlet toilet is the distance from the finished floor to the center of the outlet pipe. You must make sure that you measure from the finished floor to have an accurate measurement.

TOTO does not make a floor mounted rear outlet bowl. They do make commerical bowls that use a Sloan type valve that use a wall carrier. These would not be recommended for homes. To use any commerical flush valve in a home would require repiping the home all the way to the water meter.

Take the cover off of the toilet tank, and lay the toilet on its side to access the underside of the base. Measure from the back edge of the base to the center of the closet hole, or drain hole. Note if the measurement is 10 inches or 12 inches.

Toilet Rough-In Standard Measurements In general, the standard toilet rough-in dimension is 12”. Most toilets you can buy from the store are rated for a 12” toilet rough-in. Other common toilet rough-ins include 10” and 14”.

This height aligns with most base moldings and doesn’t cause a need to trim the waterline. Most standard toilets have a toilet rough-in of 12-inches. But some toilets require 10 or 14 inches of space from the wall to the center of the toilet flange.

If you’re just replacing your toilet and see that the center of the closet flange is only 10 inches away from the wall, just buy a 10-inch rough-in water closet. The same can be applied to closet flanges that are 12 or 14 inches away from the wall.

The clearance needed in front of the toilet bowl depends on your local plumbing codes. If your local plumbing code is under the International Plumbing Code (IPC), you’ll need to have at least 21 inches of clearance.