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KOHLER Highline Toilet Reviews 2023

We've taken time to look into the best rated KOHLER toilets. But what of the Highline collection in particular? How do they match up to the competition out there on the market, and are they a suitable choice for a residential setting? These are questions we hope to answer below.

Through in depth analysis of product specifications, flushing capability, and more, we've come up with a small list of units we feel could be a sensible option for your bathroom.

Our ratings

Image Product Flush GPF Bowl Rating? Review
HET 1.28 Elongated 86% Here
PA 1.6 Elongated 85% Here
HET 1.28 Elongated 85% Here



A model noted as having class five flushing performance which will enable it to handle bulk waste in the bowl effectively. You may be forgiven in thinking that such power requires a large quantity of water. In fact, that couldn't be further from the truth. For the K-3658-0 utilizes just 1.28 gallons of water making it much more efficient and eco friendly. This also means the Environmental Protection Agencies WaterSense guidelines are met, which consume twenty percent less water than standard units. But what does all this really mean in numbers? Well you could be saving over one hundred bucks each year in energy bills alongside thousands of galllons of water.

To give readers an idea of space requirements, the dimensions are listed as 29-1/2 inches in length by 19-5/8 inches in width by 30-3/8 inches in height. What's more, this has an elongated bowl designed to be taller than your average toilet. These are also known as comfort height.

It's two piece, finished in white, but also has the options of almond, biscuit, and black if they're to your taste.

Overall, this is a solid option at a mid tier price point with a reputable brand name behind it.


Operating on a pressure assisted flush system, this product is a powerful option that has a MaP rating of 1000, which is the highest you can go for handling bulk waste. However, many will argue that anything above five hundred is just for show.

It includes another right height bowl, going easy on your joints and muscles and making it more accessible for users with disabilities. What's more, an elongated shape will add to the comfort.

It's fitted with a chrome trip lever located on the left of its tank, and finished in white, although for those of you with more unique tastes, there are alternatives such as biscuit and black.

If you're keeping to a specific budget, you should be aware that the supoply line and seat aren't included. So make sure you price that into your decision. Seats that could work well include the K-4650-0 Lustra, the K-4694-0 Ridgewood, or the K-4636-0 Cachet silent closing seat.


Coming third in our list is the 3999. This is another highly efficient loo which uses only 1.28 gallons with each flush. So for buyers wanting something economically friendly, this could be a suitable option.

It's a residential unit that fits a 12 inch rough, and is equipped with features that make it more accessible for both senior citizens and people with mobility problems or disabilities. A taller bowl helps with getting on and off the seat, making it more accessible for everyone in the househiold or even guests.

The manufacturer lists this as another class five flush performance, and it's installation process is designed to be less time consuming thanks to its three pre installed tank bolts. Overall, this is relatively inexpensive compared to some of its competitors, and could be a good addition to your home.

Comparison table

K-3658-0 K-3493-0 K-3999-0
Type Two piece Two piece Two piece
Flush HET Pressure assist HET
GPF 1.28 1.6 1.28
Bowl Elongated Elongated Elongated
Comfort height
Color White White White
Dimensions 29.5 x 19.6 x 30.4" 38.2 x 25 x 23.7" 31.2 x 29.8 x 18"
Weight 93 lbs 102.5 lbs 93 lbs
Rating 86% 85% 85%

Considerations before you buy

Rough in distance - Measuring the size requirements should be one of the first things you do. Knowing this is essential if you want a toilet that fits. To do this, get a tape measure and note down the distance between your wall and the drain pipe. Many of you will have a twelve inch, however, there are plenty of homes which require both fourteen and ten inches.

Mounting type - Choose either a floor mounted or wall toilet. The ones that hang onto the wall are usually more complex to install as they typically work with a in wall tank and carrier system. Your household may not have the right set up for this, which may mean you require extensive renovation tasks to be carried out. If you've got the budget for this however, the aestetics are undeniable. Floor mounted options are usually the most convenient of the two whilst being less time consuming to fit.

Budget - It's easy to pick the most technologically advanced units with the most powerful flushes. What's not so simple is doing so on a specific budget. Like most consumer goods, you're going to find both low and high end options. We recommend keeping within three hundred to five hundred bucks as many of these products give a good balance between quality and value for money.

Wrapping up

KOHLER Highline toilets offer various shapes and colors to cater for numerous bathroom styles. This manufacturer has a good reputation in the industry, along with some decent innovations that improve your washroom experience. The units we've picked above are what we feel are among the best from this range. However, there are alternatives worth looking into such as the Kathryn, Persuade, Devonshire, Wellworth, Memoirs, and Cimarron collection.

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