A one-piece toilet has the bowl and tank molded into a single unit, which makes it easier to clean than a two-piece toilet, but heavier and a little different to set. Before the step-by-step, here's what the 60 one-piece toilets we sell actually measure, so you can pick one that fits your bathroom the first time. (Still deciding between the two styles? See our one-piece vs. two-piece comparison.)
| What to check | What the one-piece toilets we sell list |
|---|---|
| Rough-in | 12 inches on 57 of 60 (the other 3 don't state it) |
| Bowl shape | Elongated on 56 of 60; round on 2 |
| Seat height (floor to top of seat) | 16.69 to 17.62 inches on the 45 that list it; median 17.31 inches |
| Water per flush | 1.28 gallons or less on 53 of 60 |
| Weight | 89 to 160 lbs on the 59 that list it; median 120 lbs |
The rough-in is the distance from the finished wall behind the toilet to the center of the drain in the floor. If your old toilet is still in place, measure from the finished wall (not the baseboard) to the center of one of the bolts that hold it to the floor. TOTO, the brand behind most of the toilets we carry, notes that "the standard (or at least most common) toilet rough-in distance today is 12 inches," but 10-inch and 14-inch rough-ins exist in both older and newer homes (TOTO). Buying a toilet with the same rough-in as your old one avoids moving the drain, which is the expensive part. Many of the TOTO toilets we sell say they can be adapted to a 10-inch or 14-inch rough-in with a separately sold TOTO adapter; the product page tells you whether yours can.
Taller toilets are easier to sit down on and stand up from. For public buildings, the 2010 ADA Standards set the seat height at "17 inches (430 mm) minimum and 19 inches (485 mm) maximum measured to the top of the seat" (ADA Standards, section 604.4). Private homes don't have to follow the ADA, but it's a useful reference if anyone in your home would benefit from a taller seat. The one-piece toilets we sell that list a seat height range from 16.69 to 17.62 inches, with a median of 17.31 inches. Brands use names like "Universal Height" or "comfort height" for their taller models, so compare the measured height on the product page rather than the name.
Elongated bowls are longer; round bowls are shorter and can help in a tight powder room. Nearly all of our one-piece toilets are elongated (56 of 60). Measure from the wall to anything in front of the toilet, like a door or vanity, before you commit to the longer bowl.
The federal limit for a standard tank toilet is 1.6 gallons per flush. The EPA's WaterSense program explains that modern toilets can "use 1.28 gallons per flush or less while still providing equal or superior performance," which is "20 percent less water than the current federal standard of 1.6 gallons per flush" (EPA WaterSense). Of the 60 one-piece toilets we sell, 53 list a flush of 1.28 gallons or less, including 12 that use 1.0 gallon. Look for the WaterSense label on the product page if water savings matter to you.
Because the tank and bowl are one piece, you're lifting the whole toilet at once. The one-piece toilets we sell weigh a median of 120 lbs (89 to 160 lbs), compared with a median of 94 lbs for our two-piece toilets, which lift in two parts. Plan on two people to carry and set it.
In our catalog, a one-piece toilet without a bidet seat typically costs $900 to $1,245, with a median of $1,158 (32 toilets). One-piece toilets that come with a bidet seat have a median price of $2,444 (28 toilets); see our guide to smart toilets and bidet seats if you're considering one.
For installation, Fixr says "the average cost to install a toilet is $450, including materials and labor, and most homeowners pay somewhere between $250 and $800," with labor alone between $150 and $440 (Fixr, updated January 28, 2026). Costs vary by region and by what the plumber finds when the old toilet comes up, so get a local quote.
These are the general steps. Always follow the installation instructions that come with your toilet, since details like the bolt caps and supply connection vary by model.
Turn off the supply valve behind the toilet, flush to empty the tank, and sponge out the remaining water. Disconnect the supply line, remove the nuts from the floor bolts, and lift the old toilet straight up off the flange.
Scrape away all of the old wax, and check that the closet flange (the fitting in the floor that the toilet bolts to) isn't cracked and sits level with the finished floor. Repair a damaged or loose flange before going further. Stuff a rag in the drain opening while you work to block sewer gas, and remove it before setting the new toilet.
Put new closet bolts in the flange slots, then place a new wax ring on the flange or on the outlet under the toilet, depending on the ring style.
With a helper, line the bolt holes up over the bolts and lower the toilet straight down onto the wax ring. Press down firmly and evenly to compress the seal. Try not to rock it once it's down, which can break the seal.
Tighten the floor bolt nuts a little at a time, alternating sides, until the toilet is firm. Don't overtighten, which can crack the porcelain. Reconnect the supply line, turn the water on, let the tank fill, and flush several times while checking the base and supply connection for leaks.
Planning a bigger update? See ADA bathroom essentials for accessible measurements, or what a bathroom remodel costs. Ready to shop? Browse all toilets.
We included every one-piece toilet listed in our store on September 27, 2026: 60 listings, mostly from TOTO, plus Moreno Bath and Anzzi. Counts are product listings, and some models are listed more than once in different colors or bundles. Measurements, flush volumes and weights come from each manufacturer's published specifications, and a figure counts only when the listing states it. Prices are our regular listed prices, using the lowest-priced version of each listing. Prices and specifications can change, so check each product page before you order.
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