Item # bci2285069

Kohler Kathryn 1.28 GPF One-Piece Elongated Comfort Height Toilet with AquaPiston Technology - Seat Included

Model: K-3940-33

$898.50 - $1,343.43
Finish: Choose Finish
  • Biscuit
    7 In Stock
  • Black Black
    Black Black
    Special Order
  • White
    120 In Stock
Trip Lever Placement: Left
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Special Order

Product Overview

This product has additional required/recommended options. To configure, add to your cart.

Product Features:

  • One-piece configuration provides a uniform look and simplifies installation
  • Elongated bowl offers comfort and convenience, extending out an extra 1-1/2" compared to a round configuration
  • Covered under Kohler's 1 year limited warranty
  • The Kathryn Collection features angular lines and molded edges, capturing the classic look and feel of the 1930s
  • Constructed of durable, easy to clean vitreous china
  • Installs in a floor mounted configuration
  • Features a powerful gravity flush with AquaPiston technology
  • ADA compliant - complies with the standards for toilets set forth by the Americans with Disabilities Act
  • Comfort Height - designed for ease of use, with a higher than average bowl
  • WaterSense certified - toilet uses 20% less water than the current standard while still maintaining superior performance
  • Concealed trapway - a built in skirt hides the discharge passageway from view, for a smoother, less utilitarian appearance
  • Includes a Grip-Tight Glenbury Q3 seat and cover

Product Technologies / Benefits:

  • AquaPiston: AquaPiston single flush canister technology uses the force of gravity and a precision-engineered tank, bowl, and trapway to create a strong, efficient siphon during flushing. The canister flush valve's 3:2 ratio optimizes flush performance and resists warping and deterioration, while its durable design features 90% less exposed seal material than a standard 3-inch flapper flush valve, guaranteeing leak-free performance. The light-touch canister requires lower activation force than a flapper, and once activated, allows water to flow into the bowl from all sides (360 degrees), increasing each flush's power and effectiveness.
  • Comfort Height: Comfort Height toilets offer the greatest accessibility and ease of use with a bowl height of between 16-1/2" and 18", the same as a standard chair.
  • WaterSense Certified Product: To help make a difference on a global scale and to further its role as an industry leader in eco-performance practices, Kohler has established partnerships with a number of environmental organizations, including WaterSense. Many Kohler faucets and toilets are equipped with low-flow technology - they use less water, while continuing to meet superior performance standards.
  • Low-Profile Bolt Caps: Offer a more sleek appearance, replacing the standard gum-drop style bolt caps. Also much easier to clean around.

Product Specifications:

  • Overall Height: 28-5/8" (measured from bottom of base to top of tank)
  • Overall Depth: 28" (measured from back of tank to front of rim)
  • Overall Width: 17-1/2" (measured from rightmost to leftmost edge of toilet)
  • Bowl Height: 16-3/8" (measured from floor to bowl rim)
  • Flow Rate: 1.28 GPF (gallons per flush)
  • Water Area: 10-1/2" x 7-1/2" (inner rim dimensions of bowl, length x width)
  • Water Depth (from Rim): 5-5/8"
  • Tank Width: 17-1/2" (measured from leftmost to rightmost edge of tank)
  • Tank Depth: 7-1/8" (measured from back edge to front edge of tank)
  • Trapway (Discharge Passageway) Size: 2-1/8"
  • Distance Between Toilet Seat Installation Holes: 5-1/2"
  • Rough-In: 12"


  • K-3940: This model
  • K-3940-Touchless: This model with Touchless flush

This product is listed under the following manufacturer number(s):

*Denotes a finish or option that has been discontinued.

Dimensions and Measurements

Bowl Height
16.375 in.
28 in.
Gallons Per Flush
28.625 in.
Product Weight
45 lbs.
Rough In
12 in.
2.125 in.
17.5 in.

Included Components

Angle Supply Included
Seat Included

Characteristics and Features

Bowl Shape
One Piece
Design Features
Concealed Trapway, Chair Height
Flush Type
Gravity Flush, Siphon Jet
Installation Type
Floor Mounted
Vitreous China
Seat Front
Trip Lever Finish
Trip Lever Placement

Warranty and Product Information

Approved for Commercial Use
CA Drought Compliant
Kathryn, Comfort Height
Country Of Origin
TX Drought Compliant
WaterSense Certified
Product Videos
  • If you have been considering replacing your toilet, yet are wondering how complicated of a job this is? Take a moment and we'll show you just how simple this job can actually be.
    How to remove and install a Toilet
    If you have been considering replacing your toilet, yet are wonde...
How to remove and install a Toilet

How to remove and install a Toilet

If you have been considering replacing your toilet, yet are wondering how complicated of a job this is? Take a moment and we'll show you just how simple this job can actually be.