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.
Toilet discharge hole (vertical): Drain located at floor height; distance is zero. Toilet side-to-side buffer: Measured from the center of the toilet to either side, minimum. clearance is 15 inches to any wall or other fixture; 18 inches is recommended if the bathroom layout allows for this.
The standard rough-in dimensions for toilets is 12 inches. In older homes or small bathrooms, you'll sometimes see rough-in dimensions of 10 inches or 14 inches. Determine your bathroom's rough-in by measuring from the wall behind the toilet to the middle of the bolts on the base of the toilet.
Any plumbing professional can tell you that the standard is a 12” rough-in, and this is true for both two-piece and one-piece toilets.
Toilet Spacing and Design
At least 15 inches to any partition or side wall (measured from its center). 30 inches minimum away from any adjacent fixture (measured center to center). At least 21 inches clearance from a wall, fixture or door.
The correct measurements for a toilet is at least 21 inches in the front of the toilet, 15 inches on the sides, and at least 30 inches from anything else in the bathroom.
Recommended Distance Between a Toilet and Vanity
For the most common layout, with a toilet to the side of the vanity, the National Kitchen & Bath Association (NKBA) recommends a minimum of 15 inches from the center of the toilet to the edge of the vanity.
Overall, a standard toilet will be between 27 and 30 inches deep, with a back height of 21 to 31 inches and a width of about 20 inches. An ADA-compliant version needs to have a seat height of 17 to 19 inches. This is one reason why partitions around ADA-compliant bathrooms are different.
The standard drain line size for a toilet is typically 3 inches in diameter. This size is recommended to ensure proper drainage and to help prevent the inconvenience of clogging.
1-The Distance Between the Toilet Flange and the Wall Behind It: In order to get started, you'll need a tape measure. The water closet flange's centre should be 12 inches from the back wall. When taking this measurement, make sure you're measuring from the finished wall and not the base moulding.
Generally, it is recommended that you purchase a new toilet with the exact rough-in measurement as the original toilet.
Plugged at the U-pipe, the fresh water blocks sewer gases and lets them harmlessly leak out the plumbing vents. Every plumbing fixture needs to have a vent to work properly. Bath tubs, toilets, washing machines and kitchen sinks need the biggest plumbing vents.
Traditional toilets are 15 inches high. Comfort height toilets (or “right height” toilets) have higher seats than traditional toilets, usually between 17 inches and 19 inches. Comfort-height toilets are becoming a popular option for many households.
The clear space in front of water closets and bidets in residential structures shall be 21 inches (533 mm) minimum. For all other occupancies, the clear space in front of water closets and bidets shall be 24 inches (610 mm) minimum.
The standard toilet rough-in is 12 inches, but don't assume you have a 12” rough-in without measuring! Some older homes come with 10” or 14” rough-in sizes. You may also find 10” rough-in sizes in powder rooms, half baths, or other small bathrooms to save space.
Most toilets have larger trapways than the minimum standard for better performance. The most common sizes for toilet trapways are between 1.75 and 2 inches, although some models can be as large as 3 inches in diameter.
Most modern plumbing codes require P-trap toilets for residential installations.
Yes, It's Possible! In some plumbing setups, especially in older buildings or homes with limited space, a combined drain system might already exist. If the toilet and shower share the same drain, it's usually because of a “wet vent” arrangement.
The recommended minimum distance from the toilet's center line to the nearest side wall, partition, or fixture is 15 inches. The favored distance is 18 inches or more to the nearest side wall, partition, or fixture. If you need to save room, pushing the toilet side space to a bare minimum is often helpful.
That means there is 12-inches between the center of the toilet flange to the finished back wall. This information can be found on the toilet's specification sheet. 12 inches is the most common toilet rough-in size.
Our best overall pick, the Toto Drake Cotton Elongated Standard Height Toilet, is made with vitreous china. We recommend our best budget pick, the Swiss Madison St. Tropez Elongated Vortex Toilet, for a porcelain option.
Set-outs can vary, depending on the age of your house. Most new homes have a standard set-out of about 140-165mm, which is suited to most toilet suites.
In a toilet containing only a commode and a wash basin, such as in a powder room, a 5' X 4' size is the minimum requirement. Instead of following this size, a toilet no narrower than 3' can also be designed, keeping in mind that the minimum area required for this toilet without a shower will be 20 square feet.
International Building Codes
The IBC specifies minimum space requirements for different types of toilets. According to the IBC, the minimum clear floor space in front of a toilet should measure at least 21 inches wide and 24 inches deep.