Kohler vs American Standard Toilets: Which to Buy (2026)

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Quick answer from a licensed plumber: Match the model to the bathroom: all four score 1,000 g on the MaP list, so neither brand wins on that score. Kohler’s Cimarron is the shortest fixture here; its specification and broader warranty policy disagree, so confirm coverage rather than ranking it shorter. For a rental, compare the Wellworth: Kohler gives it five years on the china and three on parts; American Standard counts rentals as commercial with one year on each. The Champion PRO has the largest flush valve and trapway here. Both American Standard models remain in the comparison, but we are not linking their current third-party offers.

Compare by fit and warranty: the Champion PRO has the largest flush valve and trapway here, but we are not linking its current third-party offer. For a linked option with a shorter fixture, compare the Kohler Cimarron K-31621 and confirm its conflicting warranty documents; the Wellworth K-3998-T is lower at the rim and has stated home and commercial warranty terms. Check the Kohler Cimarron K-31621 on Amazon

If you are choosing between Kohler and American Standard, their mainstream two-piece toilets look alike on paper: 1.28 gallons per flush, elongated bowls, 12-inch rough-in. The differences are in the flush hardware, the seat height, the length of the bowl, and the fine print of the warranty. This page compares two models from each brand, using only Kohler’s and American Standard’s own sheets and warranties and the MaP flush list. We link the two Kohler models; the American Standard models remain as comparisons, without links to their current third-party offers.

Kohler vs American Standard at a Glance

From Kohler’s and American Standard’s spec sheets and toilet warranties, and the MaP list linked below. Rim heights are without a seat. Every linked listing was sold by Amazon.com and in stock on October 7, 2026.

Flush: Same Scores, Different Hardware

MaP scores all four at 1,000 g, so the flush test does not separate them. The hardware does. American Standard’s Champion PRO has a 4-inch flush valve and a 2-3/8-inch trapway, the largest here (valve sizes per the MaP list). Kohler’s Cimarron pairs Revolution 360 flushing with an AquaPiston canister, which Kohler says needs less force to flush than a 3-inch flapper and has 90 percent less exposed seal material. The Wellworth and Cadet PRO both have 2-1/8-inch trapways, the same as the Cimarron.

Plumber’s note: a wider trapway gives a clog more room, which is why the Champion PRO is our pick where drains have backed up before. It does not fix a problem farther down the line.

Seat Height and Bowl Length

Kohler calls its chair-height bowls Comfort Height, and American Standard calls its own Right Height. On the drawings, the Cimarron and Champion PRO are both 16-1/2 inches to the rim. For a lower seat, the Cadet PRO is 15 inches and the Wellworth K-3998-T 14-1/2. See comfort height vs standard toilets for who each height suits. The drawings do not measure length the same way. Kohler’s and the Champion PRO’s run from the back of the tank and show a gap to the wall, so the depth from the wall is about 30-1/16 inches for the Cimarron, 30-3/4 for the Wellworth and 31-1/4 for the Champion PRO (our arithmetic). The Cadet PRO drawing runs its 30-1/8 inches from the finished wall. Either way the Cimarron takes the least room, with the Cadet PRO within a fraction of an inch on its drawing, and the Champion PRO the most.

Warranty: Check the Model, Not the Brand

• In a home, American Standard’s 2025 warranty gives lifetime on the china, with 10 years on mechanical parts for the Champion PRO and 5 years for the Cadet PRO. Kohler’s Toilets and Seats Limited Warranty gives the Wellworth lifetime on the china and 5 years on mechanical parts.
• Cimarron’s documents conflict. Kohler’s K-31621 sheet names a one-year warranty, while its broader toilet policy states longer china/mechanical terms and does not exclude Cimarron. Confirm the applicable policy, seller and component with Kohler; these documents do not establish shorter coverage. The broader policy gives residential china coverage while the original purchaser owns the home and generally 10-year mechanical coverage outside its named five-year groups, subject to component exceptions. This is not confirmation that it governs this exact purchase; do not choose either policy solely to produce a warranty winner.
• In commercial use, Kohler gives Wellworth china 5 years and mechanical parts 3 years. American Standard gives 1 year on the china and 1 year on the parts, and its warranty says commercial use includes apartments and other rental units. For Cimarron, ask Kohler which policy applies and how it classifies your use; its specification and broader policy disagree.
• Fine print: Kohler’s toilet warranty (updated September 2025) is limited to the original end-user purchaser and, unless the law prohibits it, to toilets bought from Kohler or an authorized seller. It needs the original sales receipt, says in-tank cleaners void it unless properly used with Kohler’s ContinuousClean unit, and defines lifetime china coverage as lasting as long as the original purchaser owns their home. Kohler’s one-year warranty has the same purchaser and seller limits and says never to use in-tank cleaners. American Standard’s warranty covers the original purchaser, does not cover damage from in-tank cleaners, and is void if the toilet was bought from an unauthorized seller.

Repair Parts

Plumber’s note: these toilets take brand-specific flush parts, so match the part number rather than grabbing a universal flapper. Both Kohlers here use a canister with a seal; see our Kohler canister seal guide and Kohler flapper guide. For American Standard, see American Standard flapper replacement.

I send an occasional note when a new guide goes up — repairs worth doing yourself, and the parts that actually last. No spam, no course funnel; written by a licensed Georgia plumber.

Before You Buy

1. Measure the rough-in from the finished wall to the center of the drain. All four are 12-inch rough-in; see our rough-in guide.
2. Measure the room depth. From the finished wall, these four reach about 30 to 31-1/4 inches (our arithmetic from the drawings).
3. Pick the height: 16-1/2 inches to the rim for chair height, 14-1/2 to 15 for standard.
4. Rental? Compare the commercial warranty terms above before you choose a model.
5. Plan for the extras. The makers’ sheets say the seat and supply line are sold separately on all four; plan on a new wax ring too.

Swapping a toilet is a common DIY job; our toilet replacement guide walks through it.

FAQ

Is Kohler or American Standard better?

Neither wins on flush scores: all four models here score 1,000 g on the September 24, 2026 MaP list. American Standard’s Champion PRO has the biggest flush valve and trapway and a 10-year mechanical warranty in a home. Kohler’s Cimarron is the shorter fixture, but its warranty documents conflict; confirm the applicable coverage instead of ranking it shorter. For a rental, Kohler’s Wellworth has longer stated commercial warranty terms than American Standard’s; confirm how Kohler classifies your use.

Which has the better toilet warranty?

It depends on the model and component. In a home, American Standard gives lifetime on the china, with 10 years on mechanical parts for the Champion PRO and 5 for the Cadet PRO. Kohler’s Wellworth gets lifetime china while the original purchaser owns the home and 5 years on mechanical parts, with component exceptions. Cimarron’s K-31621 sheet names one year, but Kohler’s broader policy states longer terms without excluding it; confirm which applies, rather than ranking its coverage. For commercial use, Kohler gives Wellworth 5 years on china and 3 on parts; American Standard gives 1 year on each and counts rentals as commercial. Confirm Kohler’s use classification.

Do Kohler and American Standard toilets use the same flapper?

Not on these models. The Champion PRO uses American Standard’s 4-inch flush valve, and the Cimarron uses Kohler’s AquaPiston canister with a seal instead of a flapper. Plumber’s note: look under the tank lid for a part number before you buy parts; our Kohler and American Standard flapper guides show how to match it.

Which brand has the taller toilet?

Both sell chair height and standard height. On the makers’ drawings, the Champion PRO and Cimarron are 16-1/2 inches to the rim. The Cadet PRO is 15 inches and the Wellworth K-3998-T is 14-1/2. A seat adds to each number.

What about other brands?

Our best toilet guide compares TOTO, Kohler, American Standard and others. For the full Kohler lineup, see our best Kohler toilets.

Why Trust Plumbing Picks

Plumbing Picks is written by a licensed Georgia journeyman plumber. Every spec here comes from the Kohler and American Standard documents and the MaP list linked below, or from the Amazon listings we link; nothing comes from hands-on testing. On October 7, 2026, every linked listing was in stock and sold by Amazon.com. If you buy through a link we may earn a commission at no extra cost to you. Nobody pays to be included here. More on who writes this and how we pick.

Sources

• Kohler: Cimarron K-31621 specification sheet
• Kohler: Wellworth K-3998-T specification sheet
• KOHLER Toilets and Seats Limited Warranty (1420362-12, updated September 2025), KOHLER One-Year Limited Warranty (1353510-12, updated September 2025) — warranty references and the K-31621 specification rechecked October 7, 2026; the Cimarron coverage conflict remains unresolved.
• American Standard: Champion PRO 211AA.104 specification sheet, product page
• American Standard: Cadet PRO 215CA.104 specification sheet, product page
• American Standard: Lifetime Limited Warranty, Toilets and Toilet Seats (2025)
• MaP Toilet Testing: tank-type toilet list dated September 24, 2026
• Amazon listings for each linked toilet (linked above)

Bottom Line

For a home, the Champion PRO and Cimarron match on flush score: compare the Champion PRO’s bigger flush hardware with the Cimarron’s shorter fixture. Confirm Cimarron’s applicable warranty before comparing coverage; its specification and broader policy disagree. For a standard-height seat, compare the Cadet PRO and Wellworth. For a rental, consider the Wellworth K-3998-T’s tank locks and stated commercial terms, and confirm how Kohler classifies your use. Measure the rough-in and room depth first, and keep the receipt.