Kohler K-3999-0 Highline Comfort Height Toilet Review 2026
Trusted for decades by professionals, Kohler’s Highline® toilets are best selling toilet family. An ideal combination of construction, style and water efficiency, the Kohler K-3999-0 toilet is known for its elegant flared tank and subtle stepped detailing. Featuring with Kohler’s powerful canister flush valve, the toilet doesn’t sacrifice its performance for design. An innovative 1.28-gallon powerful flushing provides significant water savings (up to 16,500 gallons per year), compared to old 3.5-gallon toilets.
The Kohler K-3999-0 Highline Comfort Height Two-Piece Elongated Toilet is a feature-packed option that combines comfort, efficiency, and performance. This comprehensive Kohler K-3999-0 review will explore the design, features, and overall performance of the toilet to help you determine if it’s the right choice for your home, bathroom and waste type;
Kohler K-3999-0 Highline Comfort Height Toilet
- Product Specifications
| Feature | Details |
| Brand | KOHLER |
| Item model number | K-3999-0 |
| Country of Origin | Mexico |
| Material | Vitreous China |
| Color | White |
| Installation Type | Floor Mounted |
| Shape | Elongated |
| Seat Material Type | Plastic (Not included in Package) |
| Product Dimensions | 29.49″D x 17.99″W x 31.26″H |
| Item Weight | 93 Pounds |
| Size | -1 |
| Finish | White |
| Water Consumption | 1.28 Gallons per Flush |
| Flush Type | Gravity Flush |
| Handle/Lever Placement | Left |
| Number of Handles | 1 |
| Certification | Watersense |
| Included Components | Product Only |
| Warranty Description | One-year limited warranty |
| Rough in | 12 inches |
Made with high-quality vitreous china material, the Kohler K-3999-0 Highline toilet offers durability and resistance to staining, scratching, and fading. Its white finish adds a clean and timeless aesthetic to your bathroom.
With toilet dimensions of 29.49″D x 17.99″W x 31.26″H, this two-piece toilet features an elongated bowl shape that offers improved comfort and a seat height compared to a standard chair.
The comfort height feature of this Kohler toilet ensures ease of use for people of all ages. With a seat height comparable to a standard chair, sitting down and standing up becomes more comfortable and convenient. It is beneficial for individuals with mobility issues or elderly users who may find it challenging to use standard height toilets.
The Class Five flushing technology provides excellent bulk waste flushing performance and provides exceptional bowl cleanliness. The powerful flushing system effectively removes waste with each flush to decrease the chances of clogs and reduce the need for double flushing. Kohler claims the result will be a cleaner bowl and improved hygiene.
The Kohler K-3999-0 Highline toilet has a 12-inch rough-in which makes it compatible with most standard installations. The versatile feature ensures that the toilet can be easily installed in different bathroom layouts without additional adjustments or modifications.
This toilet meets the strict EPA flushing guidelines, including using at least 20 percent less water than 1.6-gallon toilets. With a water consumption rate of only 1.28 gallons per flush (GPF), it helps conserve water without compromising performance. The WaterSense certification not only helps reduce water usage, but it can also contribute to lower water bills and environmental sustainability.
The round-front bowl design of the Kohler K-3999-0 toilet offers an ideal solution for smaller bathrooms and powder rooms. It helps save space without compromising on comfort or performance.
The toilet is equipped with a left-hand polished chrome trip lever that adds a touch of elegance to the overall design. The trip lever allows for easy flushing with a simple press or lift.
Kohler is offering one year limited warranty for Kohler K-3999-0 toilet.
The Kohler K-3999-0 Highline toilet offers reliable and efficient performance. Its Class Five flushing technology ensures effective waste removal to reduce the chances of clogs and promote a cleaner bowl. The 1.28 GPF water consumption rate, combined with the efficient flushing system, helps save water without compromising flushing power. The elongated bowl shape adds to user comfort, while the comfort height design makes it easier for individuals of all ages to sit and stand.
Plumber Recommendation
Based on the features and performance of Kohler K-3999-0 Toilet, plumbers recommend it for small bathroom. If you have large waste to deal with, we recommend choosing another Kohler toilet with high MAP score to prevent clogging or leaking problems.
Alex Miller is a writer and researcher at ToiletsAdviser, where he spends his days doing the homework most of us dread: comparing flush systems, decoding spec sheets, and reading hundreds of owner reviews so you don’t have to. He covers toilet reviews, buying guides, and hands-on how-to content, with a soft spot for the unglamorous details — rough-in dimensions, MaP flush scores, glaze quality — that decide whether a toilet is a joy or a headache five years from now. His rule is simple: if he wouldn’t recommend it to a friend, it doesn’t get recommended here.
