Best One Piece Toilets by Flush and Rough-In

The best one piece toilets right now are led by the HOROW T0338W, a 26 x 26.6 x 15 in skirted bowl with a 17.3" ADA chair-height seat and a 1.1/1.6 GPF dual flush that keeps water use down without sacrificing pull. If you have a round-bowl bathroom and children still learning to sit down, the DeerValley DV-1F52812 is the better call, with a 28dB soft-close seat and a lighter 78 lb body that two people can actually lift.

This is not a category where anyone wins by chasing the cheapest sticker. The failure mode is a toilet that fits the space, flushes weakly, and needs a plunger twice a week for the next decade. Pick the wrong rough-in or the wrong bowl shape and you either return a 90-pound ceramic block or live with a bad seat every day.

Best one piece toilets at a glance

Who should skip a one-piece toilet entirely

One-piece toilets are heavier, harder to carry up stairs, and more expensive to replace if the porcelain cracks. If any of the following describe you, buy a two-piece instead and come back to this guide when the situation changes.

• You are installing on a second floor with a narrow staircase and no help. Every pick here weighs 78 lb or more where a weight is published, and the HOROW T0338W hits 99.2 lb.
• Your rough-in is not 10 or 12 inches. All five picks list a 12" rough-in, and only HOROW mentions a 10" version. A 14" rough-in needs a different toilet entirely.
• You need a specific finish beyond white. Every pick in this set is white with a chrome or silver button.
• You want a bidet seat with its own tank connection later. One-piece designs limit your options for retrofit hardware.

If none of those apply, a skirted one-piece is easier to clean and looks better in a small bathroom. That is the reader I wrote the rest of this for.

How I screened the shortlist

I started with the one-piece toilet listings on Amazon and pulled out the five that publish enough specifications to compare honestly.

1. Flush rating had to be stated. Any listing that only said "powerful flush" without a GPF figure or a MAP score was cut. Four of the five picks below state both, and the fifth publishes a manufacturer MAP claim.
2. Rough-in had to be specified. A one-piece toilet with an unstated rough-in is a return waiting to happen. Every pick here confirms 12".
3. Seat height had to be listed. Four of the five list a specific ADA-range height in inches; the DeerValley DV-1F52812 is the only one built around a standard, non-ADA seat, which is exactly why it earned the family slot.

Two entries survived on criteria and got cut anyway: one buried its dimensions in prose and one omitted the trapway description. Neither belongs in a decision this expensive.

The picks below are the five that survived. Each carries its trade-off in the open.

What actually decides a one-piece toilet

Most guides compare styling. Skirted looks better than skirted-with-a-shadow-line, and none of that decides anything after installation. What decides a one-piece toilet is the intersection of three numbers:

• GPF, in both modes. A 1.28 GPF single flush and a 1.1/1.6 GPF dual flush move waste differently. Dual gives you a lighter half-flush at 1.1 GPF and a full flush at 1.6 GPF. Single-flush 1.28 is a compromise designed to hit WaterSense without a second button.
• MAP score, when published. A MAP rating of 1000g is the top of the scale a listing will typically claim. Two picks here reference MAP 1000; treat that as the manufacturer's claim, not a lab report on your bathroom.
• Rough-in and depth combined. The rough-in is the distance from the finished wall to the centre of the drain. Depth is the front-to-back size of the toilet. Get the first wrong and it will not fit at all. Get the second wrong and your knees hit the vanity.

A one-piece toilet with a well-rated flush at a sensible GPF and a rough-in that matches your floor is the best one piece toilets buy no matter what the styling looks like. Get those three right and everything else is preference.

1. HOROW T0338W — Best overall

The T0338W is the only pick in this set that combines an ADA 17.3" seat, a compact 26.6" depth and a stated 12" rough-in with a 10" alternate.

Best for: a main bathroom where a compact footprint and ADA seat height both matter Skip it if: your rough-in is anything other than 12 inches and HOROW's 10-inch version does not fit either

The T0338W measures 26 x 26.6 x 15 in and weighs 99.2 lb, which is the heaviest body in this shortlist and the reason it feels solid when you sit on it. Seat height is 17.3", squarely inside the ADA chair-height range that makes standing up easier for taller adults and anyone with knee or back issues. HOROW says the trapway is fully glazed at 2", which the brand credits for waste clearance on the 1.6 GPF full flush; the half flush runs 1.1 GPF for liquid. HOROW also states both 10-inch and 12-inch rough-in versions exist, which is unusual in this price band and matters if your drain sits closer to the wall than a standard remodel expects. The one-year warranty is short but at least it is published. The trade-off against the rest of this set is weight: 99.2 lb is a two-person carry, and the DeerValley entry pick is 21 lb lighter for the same rough-in.

Pros:

• 17.3" ADA chair-height seat
• 1.1/1.6 GPF dual flush with fully-glazed 2" trapway claim
• 10" or 12" rough-in options
• Soft-close PP seat included
• Warranty published, unlike two picks here

Cons:

• Heaviest body in the set at 99.2 lb
• One-year warranty is short for a fixture
• Only listed in white with chrome button

2. DeerValley DV-1F52812 — Best for families

The lightest pick here at 78 lb, with a 28dB soft-close claim and a round bowl that suits kids and small bathrooms.

Best for: a shared bathroom with a round bowl, standard seat height and a soft-close lid Skip it if: you need ADA chair height or an elongated bowl

This is the only pick built around a standard-height round bowl rather than an elongated ADA seat, and that is deliberate: for a bathroom shared with young children, a round bowl at standard height is easier for small legs. DeerValley states dimensions of 27.8 x 24.6 x 13 in and a weight of 78 lb, which is the lightest body in this set by a clear margin, so one adult can position it during install. The dual flush runs 1.1/1.6 GPF, the same as the HOROW, and DeerValley says the soft-close seat operates at 28dB, which is quiet enough that a slamming lid should never wake anyone. The listing rates the bowl for use up to 250 lb. The skirted body has no crevices at the base, which matters when you are cleaning around a toilet a child has just missed. Trade-off against the HOROW: no ADA seat height, and the round bowl is less comfortable for taller adults on longer sits.

Pros:

• Lightest one-piece body here at 78 lb
• 1.1/1.6 GPF dual flush
• 28dB soft-close seat claim
• Fully skirted for easier cleaning
• Complete installation kit included

Cons:

• Standard seat height, not ADA
• Round bowl, not elongated
• One-year warranty
• Rated only to 250 lb per the listing

3. DeerValley DV-1F0437 — Best budget pick

The cheapest of the five and the only one advertising a rimless bowl at 1/1.28 GPF, though no warranty is stated.

Best for: a second bathroom where a rimless bowl and 1.28 GPF matter more than a warranty line Skip it if: you want a published warranty on paper before you buy

The DV-1F0437 is the cheapest of the five picks here and it is also the only one that advertises a rimless bowl, meaning the water channel that rings the top of the bowl is enclosed rather than left open under a lip. That geometry is easier to wipe down, because there is no underside to reach with a brush. DeerValley states a dual flush of 1 GPF and 1.28 GPF, which is a lower full-flush volume than the 1.6 GPF used by the top two picks; that saves water on every use but leaves less margin on a heavy flush. Dimensions are 26.6 x 26.8 x 14.5 in with a weight of 94.8 lb, and the seat sits at an ADA-range 17.5" per the height figure in the listing. The soft-close seat is quick-release, which helps at cleaning time. The trade-off is obvious: this is the only pick in the set with no warranty line published at all. For a secondary bathroom that gets light use, that risk is acceptable. For a main bathroom, it is not.

Pros:

• Cheapest of the five picks here
• Rimless bowl for easier cleaning
• 1/1.28 GPF dual flush is the lowest here
• Soft-close, quick-release seat
• ADA-range seat height

Cons:

• No warranty stated in the listing
• Lower full-flush volume gives less margin on heavy loads
• Heavier than the family pick by 16.8 lb

4. Casta Diva CD-T005 — Most versatile

Sits in the middle of this set on price and hits the standard 1.1/1.6 GPF dual flush with a MAP 1000g claim.

Best for: a guest bath that needs a MAP 1000 flush without going premium on price Skip it if: you need a published weight or warranty in the listing

The CD-T005 is the mid-price pick in this shortlist and its role is to give you the same 1.1/1.6 GPF dual flush as the HOROW at a lower position, with an elongated 17" ADA comfort-height seat. Casta Diva says the toilet meets EPA WaterSense criteria and claims a MAP score of 1000 grams via a siphon-jet system with a fully-glazed trapway. Dimensions in the listing are 25.4 x 27.2 x 14.4 in, which is a slightly deeper body than the HOROW but narrower across the width, so it can suit a bathroom where the wall-to-vanity gap is tight but front-to-back space is not. The soft-close, quick-release seat is standard for the category. What holds this back from the top spot is what is missing from the listing rather than what is in it: no published weight, no warranty line, and less complete spec coverage than the HOROW or the DeerValley family pick. If you are comfortable buying on published flush and dimensions alone, it is a strong middle option.

Pros:

• 1.1/1.6 GPF dual flush with MAP 1000g claim
• 17" ADA comfort seat
• Skirted seamless build
• Narrower width than the HOROW
• WaterSense claim in the listing

Cons:

• No published weight or warranty
• Fewer verified specifications than the top two picks
• Only listed in white

5. Casta Diva CD-W001 — Best premium

The only pressure-assist claim in this set, running a stated 1.0 GPF and offering a foot-kick flush option.

Best for: a powder room with low water pressure or a low-flow requirement Skip it if: you dislike pressure-assist noise or want a soft-close lid confirmed in the listing

The CD-W001 is the most expensive pick here and it earns the position by doing something different. Casta Diva says the flush uses an air-pressure-assisted system running at 1.0 GPF, and the brand credits that pressurised design for maintaining flush strength when household water pressure is low. Pressure-assist flushes are louder than gravity flushes; that is the standard trade-off and it applies here. The listing also describes a hands-free flush via foot-kick or side button, which is a genuine hygiene benefit in a shared or guest bathroom. The seat sits at 17.2" comfort height and Casta Diva says the siphon-jet system claims a MAP 1000g score alongside the pressure assist. Dimensions are given as 19.3 x 26.9 x 15 in. What is missing from the listing is a stated weight and a warranty line. The trade-off against the rest of the set is stark: you gain low-flow flushing power and a hands-free option, and you accept a noisier flush and thinner published specifications.

Pros:

• 1.0 GPF pressure-assist claim, lowest volume in the set
• Foot-kick hands-free flush option
• Non-electric operation
• 17.2" ADA comfort-height seat
• MAP 1000g flush claim

Cons:

• Highest price position in this set
• Pressure-assist is louder than gravity flushing
• No weight or warranty published
• Soft-close lid not confirmed in the listing

Rough-in, height and clearance: measure before you buy

The single most expensive mistake in this category is buying a toilet that does not fit. Every one of the best one piece toilets in this list quotes a 12" rough-in and only the HOROW mentions a 10" alternate, so you need to know your number before you order.

1. Measure the rough-in. From the finished wall behind the toilet to the centre of the closet flange bolts on the floor. Twelve inches is standard. Ten and fourteen exist. If your existing toilet is off-centre, measure to the flange, not to the toilet.
2. Measure the depth clearance. From the wall behind the toilet, straight out to the vanity, tub or opposite wall. Add two inches of knee room to the toilet's depth spec.
3. Measure the width. From the centre of the flange, at least 15 inches to each side to any wall or cabinet. That is code in most jurisdictions.
4. Check the seat height against who lives there. ADA chair height, 17 to 19 inches, suits most adults. Standard height, closer to 15 inches, suits young children.

Do this before you click. A one-piece toilet is not a fixture you want to return.

What the listings do not tell you

A few things every listing here leaves out that shape the buying experience:

• Bolt caps and supply lines are usually not included. The DeerValley family pick lists a wax ring, bolts, wrench and manual. The others are less explicit. Assume you will buy a stainless supply line and a wax ring anyway.
• The wax ring is a wear item. If you are installing on an old flange, replace the flange bolts and the wax ring at the same time.
• Chrome buttons scratch. Every pick here uses a chrome or silver push button. Wipe them with a soft cloth, not with an abrasive.
• Skirted bases hide the mounting. That is the point of them for cleaning, and it also means the side-access mounting used by the HOROW is not standard. Read the install manual before you cut water off.

None of this is dealbreaking. It is what you will discover on install day if you do not read the manual first.

HOROW vs DeerValley: which entry belongs in a family bathroom?

The choice between the HOROW T0338W and the DeerValley DV-1F52812 comes down to who sits on it. The HOROW is elongated, ADA chair height, and 99.2 lb of solid ceramic; it suits taller adults and a bathroom where an adult uses it more than a child does. The DeerValley is round-bowl, standard height, 78 lb, and rated to 250 lb, which suits a bathroom shared with young children who need a shorter seat and a shorter reach. Both run the same 1.1/1.6 GPF dual flush. Both publish a one-year warranty. If you have children under ten, take the DeerValley. If you do not, take the HOROW.

The verdict

The HOROW T0338W is the best one piece toilets pick for a typical remodel. It combines a 17.3" ADA seat, a 12" rough-in with a 10" alternate, a 1.1/1.6 GPF dual flush, a fully-glazed 2" trapway per the manufacturer, and a published one-year warranty. Nothing else in this set matches that combination.

Two picks flip the recommendation. If the bathroom is shared with young children, the DeerValley DV-1F52812 is the better call: a round bowl, standard seat height, 78 lb of easier-to-install ceramic and a 28dB soft-close claim. If your household water pressure is low, or you specifically want a hands-free foot-kick flush, the Casta Diva CD-W001 is the pick to take, at a higher price position and with the pressure-assist noise trade-off attached.

The two remaining picks earn a place, not a win. The DeerValley DV-1F0437 is the value option with a rimless bowl and 1/1.28 GPF flushing but no warranty on paper. The Casta Diva CD-T005 is the mid-price versatile pick whose listing simply covers less than the top two.

FAQ

Are one-piece toilets worth it over two-piece?

One-piece toilets are worth it when cleaning and appearance matter more than weight and price. A skirted one-piece has no seam between the tank and bowl, so there is no crevice to scrub and no gasket to leak. The trade-off is weight: every published body in this set weighs 78 to 99.2 lb, which is harder to carry upstairs than a two-piece.

Is a 1.28 GPF flush enough for a family bathroom?

A 1.28 GPF flush is enough for most family bathrooms when the toilet is well-designed. The DeerValley DV-1F0437 uses a 1/1.28 GPF dual flush and the manufacturer credits the rimless bowl for waste clearance. If your household includes teenagers or you are on an older drain line, prefer a 1.6 GPF full-flush option like the HOROW or the DeerValley family pick.

What rough-in do these one piece toilets need?

The rough-in these one piece toilets need is 12 inches for every pick in this guide, measured from the finished wall to the centre of the closet flange bolts. The HOROW T0338W is the only model that mentions a 10-inch version as well. If your rough-in is 14 inches, none of the toilets here will sit flush against the wall.

HOROW T0338W or DeerValley DV-1F52812: which flushes better?

Between the HOROW T0338W or DeerValley DV-1F52812, both flush at the same 1.1/1.6 GPF dual rating, so raw water volume is identical. HOROW credits a fully-glazed 2" trapway for waste clearance on the T0338W. The DeerValley pick is quieter on the seat with a 28dB soft-close claim. Pick the HOROW for flushing margin on an elongated bowl; pick the DeerValley for a round bowl and a lighter body.

What is the biggest mistake people make buying one-piece toilets?

The biggest mistake people make buying one-piece toilets is not measuring the rough-in first. Every pick in this guide needs a 12-inch rough-in and only one offers a 10-inch alternate. Returning a 90-pound ceramic toilet is expensive and slow, so measure from the wall to the centre of the flange bolts before you click, not after the delivery arrives at your door.

Buying one of the best one piece toilets is really a decision about three numbers on your bathroom floor: rough-in, depth clearance and seat height. Get those measured, then pick the flush rating that suits your household. For most remodels the HOROW T0338W is the sensible default because it publishes everything you need to check and nothing important is missing from the listing. If children still use the room, take the DeerValley family pick instead and save the ADA seat for the next bathroom you do. Either way, order the wax ring and a stainless supply line at the same time, because you will need both on install day.

Last updated: September 11, 2026. Product availability re-checked.

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