Kohler Highline Arc Curv One-Piece Elongated 1.28 GPF Toilet

The Kohler Highline Arc Curv positioning

The Highline Arc Curv (K-3493) is the one-piece variant of the Highline Classic two-piece — same Class Five flush mechanism, same value-tier Kohler brand position, but with a curved sculptural one-piece silhouette that lifts the visual presence above the utility look of the standard Highline. At $420-$580, the Highline Arc Curv is one of the lowest-priced Kohler one-pieces in the residential lineup.

The "Arc Curv" naming refers to the curved arc silhouette through the tank-to-bowl transition. It's a step-up styling from the geometric Highline Classic two-piece, while remaining solidly in the value tier. For buyers who want a Kohler one-piece under $500 and don't need the AquaPiston canister flush of Maxton/Cimarron Curv/Memoirs, the Highline Arc Curv is the practical pick.

The Class Five flush at this price tier

The Highline Arc Curv uses Class Five gravity flush (same as Highline Classic two-piece, Cimarron without AquaPiston designation, Wellworth). The key differences from AquaPiston Kohlers:

• Traditional rubber flapper at the bottom of the tank (vs vertical canister)
• Universal aftermarket parts — Korky 100 (2-inch) or Korky 2032BP (3-inch) fits directly
• Service life: 5-7 years for flapper vs 12-15 years for AquaPiston canister
• Slightly louder flush than AquaPiston due to flapper closing sound
• Lower-cost service over 20 years ($25 per flapper replacement event vs $35-$65 per canister replacement, but more frequent replacement on Class Five)

The variant matrix

What's in the box

• One-piece bowl + tank molded as single porcelain unit (~92 lbs)
• Pre-installed Class Five flush valve with rubber flapper
• Pre-installed Fluidmaster-pattern fill valve
• Chrome trip lever (front-mount)
• Tank lid (color-matched)
• Wax ring NOT included
• SoftClose seat NOT included — Bemis 1500EC universal ($35) or Kohler Brevia ($45-$60) recommended
• Installation manual

Install requirements and procedure

• Rough-in: 12 inches (standard).
• Weight: ~92 lbs as single unit — easier than 115+ lb one-pieces but two-person install still recommended.
• Standard one-piece install — see Memoirs Stately install walkthrough for the procedure.
• Wax ring: standard wax ring works; horn-style ($6) more forgiving of slightly-low flanges.
• Floor must be flat — out-of-level floor can crack porcelain. Use setting compound if needed.

What owners report

• The one-piece silhouette at this price is the value proposition. Owners frequently mention that the Highline Arc Curv "doesn't look like a $420 toilet."
• Class Five flush is reliable for normal household use.
• The curved arc styling looks more designer than the Highline Classic two-piece despite same Class Five engineering.
• Service is straightforward and affordable — universal Korky/Fluidmaster aftermarket parts at every Home Depot. Flapper replacement at 5-7 years is $5-$10.
• Standard ceramic glaze shows hard-water spots — weekly cleaning typical in mineral-heavy regions.
• 16.5" comfort height feels slightly lower than newer Kohler comfort-height models at 17.25". Taller users may prefer Cimarron at 17.25" Comfort Height.
• Service life: 25+ years porcelain.

Where Highline Arc Curv wins vs other Kohlers

Where Highline Arc Curv competes against other brands

The verdict

Buy Highline Arc Curv if:

• You want the lowest-cost Kohler one-piece elongated toilet
• One-piece silhouette + curved styling matters at this price tier
• You prefer Class Five flush (universal flapper) over AquaPiston canister
• Rental property where one-piece is a presentation upgrade over two-piece

Skip and choose Maxton if:

• You want AquaPiston canister + skirted trapway + included soft-close seat at similar price

Skip and choose Highline Classic two-piece if:

• One-piece aesthetic isn't worth $150-$300 premium
• You want easier service access to floor flange

Warranty

Kohler Highline Arc Curv residential warranty: 1 year on tank trim, lifetime on porcelain. Class Five flapper: 5-year limited warranty on rubber compound.

Pricing reality (2026)

Highline Arc Curv K-3493-0 (White): $420-$500. Home Depot: $449-$499. Lowes: $429-$479. Build.com: $399-$459. Biscuit/Almond +$40-$80.