Toilet Rough-In Measurements and Standards
Make sure the toilet dimensions will fit your space. Start by measuring the rough-in size. This is the distance between the wall behind the toilet and the center of the drainpipe or the bolts that hold the toilet to the floor. It’s best to perform this measurement before you remove the old toilet.
Measure from the wall behind the toilet to the center of one of the closet bolts (which hold the toilet down). If the toilet has four closet bolts, measure to the center of one of the rear ones. Then measure from the center of the mounting holes to the back of the new toilet you're considering. Compare these two measurements. If the base of the new toilet is shorter than the distance between the rear bolt holes and the wall, it should fit. In small bathrooms where space is tight, also measure from the sides of the flange bolts to the sidewalls or other objects to assure side-to-side clearance.
The standard rough-in is 12 inches, though you may encounter 10-inch and 14-inch rough-ins in older homes. You should find the rough-in measurement in the new toilet’s product information.
Toilet Models: One Piece or Two?
Toilets are made in one- or two-piece models. Most toilets are two piece, meaning that the bowl is bolted to the tank. Two-piece toilets are generally less expensive than a one piece. Both function comparably, though a one-piece toilet may be easier to clean. If installation parts aren't included, make sure you purchase all the toilet parts you'll need: a toilet seat, a wax ring with a sleeve, closet bolts and bolt caps.
Wall-mount or wall-hung toilets are another style option that's becoming increasingly popular in modern homes. Just remember that these units require modifications to the plumbing/waste system and additional bracing in the wall.
Types of Toilet Bowls
Thinking about an elongated vs. round toilet bowl? There are a few things to consider. Elongated bowls are usually 2 inches longer than round bowls and offer additional comfort. Round bowls are generally less expensive and work well in small spaces. As with rough-in standards, make sure your space will accommodate an elongated bowl before you shop.
The bowl height is generally 14 to 15 inches high measured from floor level (without the seat). Taller bowls are available in the height of a standard chair (16 to 19 inches) for comfort and accessibility. Taller bowls are also compliant with the Americans With Disabilities Act (ADA) standards.
Other bowl features to note:
- Sanitary Bar: Found on two-piece models, the sanitary bar blocks liquid from collecting under the tank at the back of the bowl.
- Trapway: The snakelike tubing on the sides of your toilet through which water flows. A larger trapway diameter (2-3/8 inches) reduces the chance of clogging and overflow.
Toilet Tanks and Flushing Systems
Almost all toilets have a similar tank capacity. When choosing a tank, you'll have to consider the size of the flush valve and the positioning of the flush lever as well as the flushing system.
The flush valve, which is located at the center of the tank, is activated by the flush lever and releases the water held in the tank. The larger the flush valve, the higher the rate of water flow. Flush levers are positioned either on the side, front or top of the tank.
The pressure-assisted and gravity-flush systems are the two standard flushing systems available:
- Pressure-Assisted Flush System: Pressurized air forces water into the bowl when flushed, reducing the chance for clogs. This system is noisy and expensive, and it may require costly maintenance.
- Gravity Flush System: The most common and simplest system uses the water weight to generate flushing pressure. The pressure forces everything from the tank into the bowl and through the S-shaped trapway. A siphoning action completes the flush. This flushing system is quieter and requires less maintenance than a pressure-assisted flushing system.
Additional toilet technology includes:
- Dual Flush: This is a relatively new system for saving water without sacrificing efficiency. There are two flushing options for a full or partial flush (1.6 gallons per flush and 1.1 gallons per flush).
- Waterless Toilets: Where water or plumbing isn't available or when portability is required, a self-contained waterless unit is an option.
- Touchless Toilets: This technology allows you to flush the toilet with a simple hand signal over the sensor button without touching it.
Choose the Best Toilet Flapper
To select the right toilet flapper size, you’ll need to find one that fits your toilet dimensions. Simply measure the diameter of the drain. If the diameter is 2 1/2 inches, for example, you’d need to purchase a 2-inch toilet flapper.
Toilet Seats
Most toilets come in separate pieces and don't include the seat. Choose a seat that complements the color of the toilet and the décor of your bathroom. Think about the following items when choosing your seat:
- The seat shape depends upon the shape of the bowl: round or elongated.
- Seats are available in real wood, molded wood composition, cushioned vinyl, plastic or polypropylene.
- Slow-close toilet seats are quiet and safe (they won't slam down).
The best toilet seats offer such amenities as a warm water stream, a heated surface, warm air drying, a deodorizer or a padded surface. Additional water and electrical hookups are required for these luxury items.
Toilet Height
The standard height for a toilet is between 14 and 16 inches from the bathroom floor. However, you can also purchase shorter toilets that are a more comfortable height for children and shorter adults, as well as taller toilets, which are easier to use for taller adults or those with mobility challenges.
Toilets and Water Usage
By federal law, new toilets can’t use more than 1.6 gallons of water per flush (GPF). High-efficiency toilets (HET) use even less.
Toilets with the US Environmental Protection Agency’s (EPA) WaterSense® label rate high in both water efficiency and flushing effectiveness. They meet strict flushing performance guidelines established by the EPA and use at least 20% less water than standard 1.6-gallon toilets.
Urinals and Bidets
Other sanitary devices are available to equip your bathroom.
A urinal is a water-efficient, wall-mounted unit. Most urinals are found in commercial or retail settings. A bidet, which provides a convenient facility for personal cleansing, is becoming more common as an added fixture in many new-construction and remodeling projects. It's a separate fixture that's usually placed beside the toilet.
Bidet Toilet Seat
A bidet toilet seat, also known as a washlet, is an affordable option that gives you the look and feel of a toilet with the functionality of a bidet. Bidet toilet seats replace existing toilet seats and therefore don’t take up any additional space. Features vary but can include a heated seat, deodorizers, warm air dry, remote controls and more.
Bidet Attachment
A bidet attachment is a toilet-mounted device that allows the toilet to function as a bidet. It’s an economical solution for those who want the benefits of a bidet and it’s easy to install.
The term Japanese toilet is often used to define the technology that combines a traditional toilet with modified bidet functionality, due to their popularity in Japan. The name TOTO is often used, but this is a specific brand name rather than a distinctive type of toilet.