The Best One-Piece Toilets of 2026: 7 Picks Ranked by Manufacturer Specs and Installer Consensus

By Ariel, last updated July 1, 2026.

A one-piece toilet has one job that a two-piece cannot do: it has no seam between tank and bowl, so the joint that collects mineral crust and pee-mist in a two-piece simply isn’t there. That is the only reason to pay the premium. Everything else, the flush, the height, the bowl shape, the trapway, you can buy in a two-piece for less money.

This roundup evaluates seven one-piece toilets that are widely available in 2026, based on manufacturer specs, MaP testing reports, and public installer forum consensus (Terry Love plumbing forum, Home Depot pro-desk reports). Hard-water and humid-climate durability notes below draw on published installer commentary rather than a single controlled test setting.

The Ultramax II is the one to buy

If you can spend $500 to $700, the TOTO Ultramax II is the one to buy. Tornado Flush, MaP score of 800, universal height (17.25″), and TOTO’s Costa Mesa parts warehouse keeps spares in circulation through Build.com and Plumbersstock.

For a concealed-trapway look at half the TOTO price, the Kohler San Souci is the cleanest concealed-trapway one-piece under $400, with a smaller footprint than most.

In a bathroom under 50 square feet, the Swiss Madison St. Tropez is the smallest credible one-piece in this roundup, and the cheapest. The catch: proprietary parts get harder to source after year three, per Terry Love forum consensus.

Our picks at a glance

Toilet	Height (rim)	Shape	Flush	MaP score	Skirted	Approx. price	Best for
TOTO Ultramax II	17.25″	Elongated	1.28 GPF Tornado	800	No	$560 to $640	The “no regrets” pick
Kohler San Souci	16.5″	Elongated	1.28 GPF AquaPiston	800	Concealed trapway	$370 to $430	Best concealed-trapway under $500
Swiss Madison St. Tropez	17″	Elongated	dual-flush 1.1/1.6 GPF	500	Yes (skirted)	$289 to $329	Smallest footprint
American Standard Compact Cadet 3	16.5″	Elongated	1.28 GPF Cadet 3	See note	No	$355 to $410	Chair-height value pick
TOTO Carlyle II	16.5″	Elongated	1.28 GPF Tornado	1000	Yes (full)	$680 to $780	Skirted + 10/12/14 rough-in via Unifit
Kohler Santa Rosa	16.5″	Elongated	1.28 GPF AquaPiston	1000	No	$540 to $610	Best Kohler one-piece flush platform
Woodbridge T-0001	17″	Elongated	1.28 GPF dual-flush	1000	Yes (full)	$329 to $389	Skirted look on a budget

Prices observed at Home Depot, Lowe’s, Build.com, and direct from manufacturer in July and August 2026. Skirted models tend to run $80 to $150 over the unskirted equivalent from the same brand.

How we picked the best one-piece toilets

Picks were narrowed from currently sold one-piece SKUs at Home Depot, Lowe’s, Build.com, and manufacturer-direct as of July 2026. Every unit here is in active production; none are discontinued at the time of writing.

Four criteria drove the shortlist. Flush performance: MaP testing lab reports (map-testing.com, most recent 2025 dataset) for the polyethylene-ball score, cross-checked against manufacturer spec-sheet flush claims. Cleaning experience: skirted vs concealed-trapway vs standard trapway silhouette per manufacturer product-page descriptions, since side-panel geometry is what determines wipe time. Parts availability: catalog depth and third-party stock at Build.com, Plumbersstock, and the Terry Love plumbing forum’s parts-source threads. Long-term durability signal: warranty terms per manufacturer, plus recurring failure patterns reported in installer forums (Terry Love and Home Depot pro-desk Q&A).

The case for one-piece (and when two-piece is actually smarter)

The single feature that justifies a one-piece is the seamless base. There is no tank-to-bowl gasket, no exposed bolts at the back of the bowl, and (on skirted or concealed-trapway models) no exposed trapway curve on the side. When you wipe the base, the cloth runs in one motion from the back of the tank to the front of the bowl. On a two-piece, the cloth catches the tank bolts, the rubber gasket lip, and the trapway hump. Manufacturer marketing (Kohler, TOTO) and Terry Love forum consensus both frame the one-piece premium as buying back cleaning time on that back-of-bowl seam.

If you have ever taken a toothbrush to the back of a toilet bowl on cleaning day, you will pay extra to never do it again.

The downsides are real. One-pieces weigh 95 to 110 pounds versus 60 to 80 for the comparable two-piece, which makes solo installs a back injury waiting to happen. If the porcelain cracks at the tank or the bowl, you replace the whole unit. And model selection thins out under $300.

A two-piece is the smarter buy if you are installing alone, if you have a 10″ or 14″ rough-in, or if your budget is under $300 and you want something that is not Swiss Madison.

Our top pick: TOTO Ultramax II ($560 to $640)

The 17.25″ rim sits within the ADA 17 to 19 inch comfort range, and the 28″ depth fits most standard bathrooms without crowding the door swing. TOTO calls it universal-height and the spec sheet backs the label.

The Tornado Flush sends rim water through two nozzles instead of perimeter holes, which TOTO’s product literature credits for keeping the underside of the rim cleaner longer than a conventional rim-hole design. Terry Love forum threads on rim mineralization in hard-water regions echo that pattern.

MaP score is 800 per the May 2025 MaP report. The Kohler Santa Rosa, TOTO Carlyle II, and Woodbridge T-0001 further down this list score MaP 1,000, so the Ultramax II is not the flush-performance leader in this roundup – its edge is price, parts availability, and TOTO’s build track record. The 1.28 GPF flush earns the TOTO stealth-quiet reputation cited in installer commentary.

What to watch. The stock trip lever is plastic; TOTO sells a brushed-nickel metal replacement for around $22, a common upgrade cited on Terry Love threads. The SoftClose SS124 seat is included in the box, per TOTO spec sheet SS-01779 v.04 – the “MS604124CEF” and “MS604124CEFG” models both ship with SS124.

Parts: the replacement flapper (TOTO THU416), fill valve, and flush valve cartridge are all stock items at Build.com and Plumbersstock, sourced from TOTO’s Costa Mesa warehouse.

Best under $500: Kohler San Souci ($370 to $430)

The San Souci is the cleanest-looking one-piece you can buy for under $400. Kohler describes it as a concealed-trapway design (per the K-5172-RA spec sheet header and product-page title), which means the trapway curve is hidden behind a smooth ceramic side wall – distinct from Kohler’s separate “skirted trapway” category (which runs flat all the way to the floor). Visually, it still reads more expensive than the price.

The flush is Kohler’s AquaPiston canister, which delivers water from a full 360-degree rim wash. Different mechanism, similar real-world result to TOTO’s Tornado: rim-hole crusting is reduced versus a conventional flapper-based two-piece. MaP score is 800.

Seat upgrade note. The standard San Souci ships with a Quiet-Close seat. Owners on Terry Love threads commonly upgrade to the Kohler Cachet Q3 (around $48 retail as of July 2026) for the quick-release hinge.

The 16.5″ rim is shorter than the Ultramax II. For most adults it is fine. Users over 6’1″ or with knee issues will generally prefer the Ultramax II’s 17.25″ rim.

Parts story: Kohler’s parts network is the deepest in North America. Home Depot pro desks stock San Souci flapper and fill-valve parts through Kohler’s dealer channel, which matters at year five and beyond.

Smallest footprint: Swiss Madison St. Tropez ($289 to $329)

The St. Tropez is 26″ front-to-back, which is the shortest one-piece elongated in the 2026 mainstream catalog. For comparison, the Ultramax II is 28″ and the Carlyle II is 28.5″. Two inches sounds small until you are putting a toilet into a 56-inch-wide half-bath with the door swinging in.

This is a Chinese-manufactured dual-flush 1.1/1.6 GPF one-piece sold direct, mostly through Wayfair, Build.com, and Amazon. It is not a TOTO and this guide will not pretend it is. The MaP score is 500 – lower than the other picks but still above the 350 threshold MaP considers acceptable for residential use.

The price shows up in the porcelain glaze, which is slightly less crisp than the Kohler or TOTO up close (invisible from a foot away), and in the top-mounted plastic flush button, which works but does not feel premium.

Silhouette note. The Swiss Madison product page describes the St. Tropez as having a “Fully Glazed and Skirted Trapway” – verbatim. The skirted profile is part of what makes it read cleaner than the price suggests.

Parts story: this is the one. Swiss Madison parts ship from a single US warehouse and are typically in stock, but the proprietary flush valve has no third-party replacement. If Swiss Madison changes their flush valve design at year five, the toilet effectively ages out – a trade-off installer forums flag repeatedly for the price bracket.

Best chair-height: American Standard Compact Cadet 3 One-Piece ($355 to $410)

The Compact Cadet 3 one-piece (SKU 2403128.020) sits at American Standard’s “Right Height” of 16.5 inches at the rim, no skirt, no design statement, just a competent porcelain box with a compact elongated bowl for tighter bathrooms. It functions as the mainstream chair-height baseline against the more design-driven picks. Retail pricing observed at Shell Lumber and other plumbing retailers as of July 2026 sits in the $355 to $410 band, the lowest entry price in this roundup for a seat-included one-piece.

Cadet 3 gravity flush at 1.28 GPF, oversized 3-inch flush valve, 2-1/8-inch fully glazed trapway, per the current americanstandard-us.com product page. This is a gravity-flush toilet rather than a pressurized or high-MaP-rated performer: American Standard does not publish a MaP score on the current product page, and third-party MaP figures for this SKU are inconsistent (some cite 800 g, some 1,000 g), so we do not claim a specific MaP number here. The realistic read is a dependable everyday flush, not a flush-performance leader like the Carlyle II or Santa Rosa further up this list. The surface is American Standard’s EverClean antimicrobial glaze.

What earns it the slot is price plus the parts network. It is the cheapest way into a one-piece, seat-included, chair-height toilet in this roundup, and American Standard parts are stocked at every Home Depot, Lowe’s, and independent plumbing supply house in the US. If the fill valve goes at year seven, replacement parts are Saturday-morning easy.

Seat included. The Compact Cadet 3 one-piece ships with a slow-close, easy lift-off seat and lid, per American Standard product-page copy: “Includes slow-close seat and lid for silent, no-slam convenience.”

Best skirted TOTO: TOTO Carlyle II ($680 to $780)

The Carlyle II is the skirted sibling of the Ultramax II: same Tornado Flush, same parts network, and one meaningful upgrade. The Carlyle II scores MaP 1,000 per the May 2025 MaP report against the Ultramax II’s 800, and it is Unifit-compatible for 10-inch and 14-inch rough-ins via the TSU01W.10R and TSU01W.14R adapters per TOTO spec sheet SS-01809. The side panel encloses the trapway curve and gives the unit a continuous profile from tank to floor.

You pay about $120 over the Ultramax II for the skirted look plus the rough-in flexibility. If you have a non-standard rough-in and a floor-mount budget in this range, the Carlyle II’s Unifit system is the shortest path.

What to watch. Same plastic trip lever as the Ultramax II; the same brushed-nickel metal replacement fits the Carlyle II per TOTO parts documentation.

Availability has thinned out at major retailers; if you want one, check TOTO direct or call your local plumbing supply.

Highest MaP score: Kohler Santa Rosa ($540 to $610)

The Santa Rosa (K-3810-0) is the Kohler one-piece to buy if flush performance is the only thing that matters. Kohler’s AquaPiston canister pushes water from a full 360-degree rim wash and the Santa Rosa scores MaP 1000 on Kohler’s spec sheet. That is the top of the MaP scale.

At MaP 1000, the Santa Rosa sits alongside the TOTO Carlyle II and Woodbridge T-0001 at the top of this roundup for evacuated-mass performance. Real difference for households with kids in potty training or anyone who routinely needs a courtesy flush.

Unskirted, with the trapway exposed on the sides. Buyers give up the wipe-time advantage of the skirted or concealed-trapway picks for the AquaPiston flush platform and the wide Kohler service network.

The 16.5″ Comfort Height rim measures 17.25″ with the seat, which puts it in standard chair-height territory. The 12″ rough-in is the only option and the unit ships in a single box with a slow-close seat included.

Seat upgrade note. The included slow-close seat is the basic Kohler unit rather than the Cachet Q3. Owners who want the quick-release hinge typically swap seats after install.

Best skirted under $400: Woodbridge T-0001 ($329 to $389)

Woodbridge sources porcelain from the same factories that supply the lower-tier Kohler and American Standard lines, then sells direct through Amazon and their own site. The T-0001 is their dual-flush elongated one-piece.

Amazon and Home Depot review patterns for the T-0001 skew positive on flush strength and skirted appearance at the price point. MaP score is 1000 on the full-flush position (1.28 GPF); per the woodbridgebath.com T0001-MB spec table, the dual-flush range is 1.0-1.28 GPF, meaning the half-flush is 1.0 GPF and is best used for liquid loads only.

What you get is the fully skirted look without the legacy brand markup. What you give up is parts availability after warranty: Woodbridge stocks its own parts in California, but if they change a flapper design at year seven, replacement is not guaranteed. Same trade-off as Swiss Madison, one price bracket up.

Skirted vs unskirted

A skirted trapway means the side of the toilet is one continuous panel from tank to floor. Unskirted means you can see the curve of the internal flush channel sticking out the side of the bowl. The plumbing is identical; the cleaning experience is not.

Skirted models wipe faster. The side panel is one flat surface, so a cloth runs across it the way it runs across a wall. Unskirted models have a 1.5 to 2 inch hump on each side where the trapway is, and that hump catches whatever the cloth was trying to push off the porcelain.

The trade-offs of skirted are price ($80 to $150 over the unskirted equivalent) and bolt access. A skirted base hides the closet bolts under porcelain caps that pop off with a screwdriver. Unskirted bolts are right there.

If your budget allows skirted, get skirted. The cleaning hours pay off after about two years.

Buyer’s guide

Rough-in

Measure from the finished wall behind the toilet to the centerline of the closet bolts that hold the toilet to the floor. Most American homes built after 1970 are 12 inches. Older homes, especially pre-1960, may be 10 inches or 14 inches.

A 12-inch toilet on a 10-inch rough-in will not seat against the wall; you will have a 2-inch gap. A 10-inch toilet on a 12-inch rough-in fits but looks pushed forward. Match the toilet to the rough-in, do not guess. Of the seven picks in this roundup, the Kohler San Souci ships in 12-inch rough-in only (per Kohler K-5172-RA spec PDF, Technical Information: “Rough-in: 12″ (305 mm)”). The Swiss Madison, Woodbridge, and Kohler Santa Rosa only ship in 12-inch. The TOTO Carlyle II is the only pick in this roundup with 10-inch and 14-inch rough-in options, via the TSU01W.10R and TSU01W.14R Unifit adapters per TOTO spec sheet SS-01809. If you are working around a non-standard rough-in, the Carlyle II’s flexibility is a meaningful advantage worth naming.

Shape

Six of our seven picks are elongated. Elongated bowls are about 2 inches longer front-to-back than round bowls, and most adults find them more comfortable to sit on. Round bowls only make sense if you have a bathroom under 30 square feet and you need every inch of floor space.

Height

There are three real height categories. Standard (14 to 15 inches rim) is what older homes have. Comfort or chair height (16.5 to 17.25 inches rim) is what most new toilets are. ADA accessible (17 to 19 inches total, including the seat) is required in commercial accessible bathrooms and is what most users with knee issues should pick.

Add the seat. A standard plastic seat adds about 0.5 inches to the rim height. A premium SoftClose seat adds about 0.75 to 1 inch. Manufacturers sell on rim height but you sit on seat height. Comfort-height toilets with a thick seat can read as ADA-tall, which works for some bodies and not others.

Flush mechanism

For one-piece toilets at this price range, the three flush technologies you will see are:

1. Tornado Flush (TOTO): two-nozzle rim wash. Quieter and cleans the rim better.
2. AquaPiston (Kohler San Souci and Santa Rosa): canister-fill flush valve with 360-degree rim flow. Slightly faster bowl clear.
3. PowerFlo (American Standard) and basic siphonic/dual-flush (Swiss Madison, Woodbridge): conventional flapper-and-tower with a 3-inch valve. Reliable, louder, parts are universal.

If you replace flappers yourself once a decade, the PowerFlo and basic siphonic options are easier to maintain. If you would rather not think about it, Tornado or AquaPiston.

MaP score

MaP (Maximum Performance) is an independent testing protocol that measures how many grams of polyethylene balls a toilet can clear in a single flush. The maximum score is 1000. Anything above 600 is solid for a residential toilet. Anything above 800 is what we recommend if you have kids, large dogs, or any household member with regular GI issues.

FAQ

Are one-piece toilets harder to install than two-piece?

Yes, mostly because of weight. A typical one-piece runs 95 to 110 pounds in one piece; a two-piece splits into a 50-pound bowl and a 30-pound tank. The plumbing connections (closet bolts, wax ring, supply line) are identical, but the lift, the carry from box to bathroom, and the set-down are all harder on a one-piece. Plan for two people, even if one is just spotting.

Do one-piece toilets clog more easily?

No. Clog risk depends on trapway diameter (the bend the waste passes through) and flush volume, not the toilet’s number of pieces. Among our picks, the Kohler Santa Rosa has the largest trapway and the Swiss Madison St. Tropez has the smallest. The Santa Rosa clogs less often. Both are one-piece, which tells you the number of porcelain pieces is the wrong variable.

How long do one-piece toilets last?

The porcelain outlives the house. Original American Standard one-pieces from the 1960s remain in service in older US homes per Terry Love threads on legacy fixtures. What fails is the seat (every 3 to 5 years), the flapper or canister gasket (every 5 to 7 years), the fill valve (every 7 to 10 years), and the trip lever or button (every 5 to 8 years), all of which are user-replaceable in under 30 minutes.

For one-piece specifically, parts availability matters more than for two-piece, because a discontinued flush valve can end the toilet’s life. Over a 15-year horizon, TOTO, Kohler, and American Standard parts stay in the catalog. Swiss Madison and Woodbridge parts commitments beyond the warranty term are less certain per public installer commentary.

What is the difference between skirted and standard one-piece?

A skirted one-piece has a continuous flat side panel covering the trapway curve. A standard one-piece exposes the trapway bulge on each side of the bowl. Plumbing is identical; cleaning is faster on skirted. Full breakdown above.

Is a one-piece worth the extra money over a two-piece?

If you will keep the toilet for at least 5 years, yes: the cleaning time savings add up. If you are renovating to sell, also yes, because a one-piece reads as a more premium fixture in listing photos.

If you are a landlord replacing a toilet between tenants, no. Two-piece is cheaper and ships cheaper. The cleaning difference matters less when you are not the one cleaning weekly.

Sources & references

• MaP Testing: flush performance scoring methodology and 2024 lab results for MaP scores and the 1000g pull test protocol
• EPA WaterSense: high-efficiency toilet standards for the 1.28 GPF baseline and labeling rules
• TOTO USA: Ultramax II and Carlyle II spec documents
• Kohler: San Souci, Santa Rosa, and parts lookup
• American Standard: Compact Cadet 3 One-Piece product page and spec sheet
• IAPMO: Uniform Plumbing Code 402 for fixture installation

See also on My Best Toilet

• Best elongated toilets for round vs elongated bowl sizing across both one-piece and two-piece options
• One-piece vs two-piece toilet for the head-to-head comparison if you have not decided yet
• Best tall toilets for seniors and elderly for chair-height and ADA-height picks specifically
• Comfort height vs standard toilet for the rim-height-vs-body-height chart we use to pick heights
• TOTO vs Kohler for the brand-vs-brand comparison if you are between Ultramax II and San Souci
• Best toilet seats for aftermarket upgrades if you want a heated seat or a premium slow-close hinge (the Compact Cadet 3 and San Souci ship with slow-close / Kohler-branded slow-close seats included)