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5 Best Low Flow Toilets (Most Efficient Flush 2024 & Ratings)

Having a contemporary bathroom in your home doesn't just refer to the interior design and the theme. There are certain features and functions included in the hardware you purchase to ensure everything is appropriately modernized too. Low flow toilets are a great example of this, with smart flushing technology built in to minimize water consumption.

Depending on how much water your current toilet uses, you could stand to save up to sixty percent according to some calculations. That's a significant difference that can make a large dent in your monthly utility bills.

We've hand picked a few of our favorites below.

Our picks

  1. TOTO Ultramax II
  2. TOTO Drake II
  3. KOHLER Tresham
  4. KOHLER Memoirs
  5. American Standard Town Square

TOTO Ultramax II MS604114CEFG

The Ultramax II has many of the qualities we look for. Strong flushing power, coupled with a solid bowl rinse, and good efficiency.

It's ADA, WaterSense, and CALGreen compliant and the bowl is elongated in shape.

Well worth looking into further if performance is high on your list of priorities. However, it loses a couple of points in our view by not having skirting around the bowl to cover the trap.

Compare toilets

TOTO Ultramax II TOTO Drake II KOHLER Tresham KOHLER Memoirs American Standard
Town Square
Model number MS604114CEFG CST454CEFG K-3950-0 K-6669-0 2817.128.020
Rough in 12" 12" 12" 12" 12"
Trip lever .
GPF 1.28 1.28 1.28 1.28 1.28
WaterSense .
MaP 800g 800g 1000g 1000g 1000g
Rim height Height without seat
16-1/8" 16-1/8" 16-1/2" 16-1/2" 16-1/2"
Elongated .
Dimensions 28 3/8 x 16 1/2 x 28 3/4" 28.8 x 16.5 x 29.4" 28.5 x 16.5 x 14.5" 31.4 x 28.2 x 20.1" 29.8 x 15.2 x 31.1"
Weight 99 lbs 94 lbs 72.8 lbs 101 lbs 89.4 lbs
Concealed trap
One piece
Two piece
Floor mount .
Wall mounted
Colors White Cotton, Beige, Bone White, Biscuit, Bone White, Sandbar, Black White
Rating 88% 86% 86% 84% 84%

What is a water saving toilet?

When manufacturers descibe a toilet as low flow, they are saying the amount of water that passes through the bowl from the tank is lower in volume than standard units. Nothing really changes in terms of how they function either. They still use either gravity or air assist mechanisms to clear waste. In fact, compared to many older style tanks, they can help you save thousands of gallons per year, which also plays a role in reducing the amount of money you spend on your utility bills.


You stand to save up to sixty percent of the water you were previously using. If you have a large family, this can translate to tens of thousands of gallons of water. Over the products lifetime, this could result in you saving thousands of dollars too. Get yourself a durable product that lasts years, and you will probably recoup the amount of money you spent on making the upgrade.

Toilets account for around 30% of the average households wasted water according to the EPA. So the more people that replace their older 5.0 and 3.5 gallon units, the bigger the impact it will have on the environment.

What is a WaterSense toilet?

The WaterSense label is a label given to sanitary ware that meets specific water usage criteria given by the Environmental Protection Agency. This is not limited to toilets alone. They also have criteria for shower heads and faucets too.

In order for manufacturers to place this label on their products, they must meet a set of requirements that vary depending on flush type.

For a single flush mechanism, the amount of water used can't exceed 1.28 gallons. For dual flushing systems, they must not exceed 1.28 gallons after the average of their full and partial flush is taken.

To encourage consumers to replace their older, inefficient products, with newer economically friendly versions, there may even be tax rebates available to you.

List of reviews

TOTO Ultramax II MS604114CEFG

This is a toilet that utilizes 1.28 gallons of centrifugal force with the power of gravity to rinse the bowl. This is also known as a tornado flush and is known to be highly effective in removing bacteria and waste from difficult to reach areas. This means your cleaning duties will be less frequent.

It has a great one piece design that is less time consuming, and far less complex to set up. What's more there is no joint or exposed material between the tank and bowl for anything to go wrong in terms of leaking. The seamless design improves the style and modernizes it in our view.

It's elongated bowl gives people the necessary space to conduct their business in comfort. However, you'll need to ensure you have a bathroom big enough to accommodate it. The measurment from the floor to the seat is tall enough to be given the comfort height label and meet ADA standards too.

You can say goodbye to seating which slams shut, causing unecessary noise and damage to the rim too. For it comes equipped with a slow closing seat as well.


The Drake II is another top product from the Toto brand. Unlike the MS604114CEFG, this has a two piece design, with the tank and bowl separated. This may increase the amount of time taken to set it up.

It achieves strong flushing performance despite using small amounts of water. A 1.28 GPF flow rate results in a 800 gram score on the MaP scale. The double cyclone system is partly responsible for this.

The 16-1/8 inch rim height, coupled with a seat ensures it meets Americans with Disabilities criteria, making it far easier to sit down and stand up in your bathroom visits. This extra height will be appreciated by senior citizens, taller than average people, and people with joint and muscle problems.

There is plenty of choice when it comes to matching your washrooms color theme. You can opt for a basic cotton white, which tends to be a sensible choice in most interior designs, however, there are some great alternatives such as sedona beige, colonial white, and bone.

The seat isn't sold with it, so you'll need to purchase one separately. We recommend buying either a quiet closing seat or a bidet. The SS154#01 is one such option. Just make sure you're aware of the additional expenses involved with buying these extra pieces of sanitary ware.

KOHLER Tresham K-3950

Kohler are one of our favorite brands and certainly among the market leaders in this industry. The Tresham is a product that holds its own against the competition for various reasons.

First of all, the design is completely unique in comparison to many toilets. It consists of the K-4899 tank and the K-4799 bowl. They both have beautiful ridging details which certainly adds a unique touch. It has what we'd describe as a more traditional style, but it looks good, wouldn't look out of place in a modern household.

It's two piece, has a comfort height bowl that's elongated, and usess just 1.28 gallons on a AquaPiston flushing mechanism. The seat and supply aren't included, so be sure to plan your budget around that.

What's more, if anything go wrong with your purchase, you're protected by a limited one year warranty.

KOHLER Memoirs K-6669-0

The Memoirs toilet offers a number of features and specs that enable it to stand out from the crowd. As you'd expect appearing in this list, it's eco friendly, but what else does it have going for it?

Externally, it has a fairly similar design to the Tresham. Ridging adding a personal touch at the base of the bowl and on the tanks lid. Then there is a polished chrome trip lever at the front. Perhaps the best visual spec is the fact that the trapway is concealed. This smoothes over the sides, removing the outline of the pipes.

It uses 1.28 gallons per flush, and is chair height to improve user comfort and making sitting down a lot easier on the joints for most adults, especially senior citizens.

The built in canister valve reduces the chance of it clogging up, and the 1000 gram MaP score highlights this. This is the highest rating you can get from them.

The dimensions given are 31.4 by 28.2 by 20.1 inches, and it weighs 100 lbs. It will fit a standard twelve inch rough, includes a 11-1/8" by 8-1/2" water spot, plus a two inch trap passageway.

American Standard Town Square 2817.128.020

Upon first look, the Town Square has quite an unusual style. It's quite blocky with smooth sides hiding the pipes. Not only does this improve the aesthetis, but it will ensure there is no where for dirt to hide when cleaning, making your bathroom a more hygienic and fresh smelling place to visit.

The bowl is right height and elongated which provides great support for the legs, joints, and muscles. The extra inches given from the base to the seat will go a long way in improving accessibility for all. The surface is also coated in EverClean gloss which will ensure less waste sticks to the bowl. Ceramic china without this can be quite porous, which enables microbes to find gaps to thrive in.

It will fit a 12" rough in size, has a fully glazed two inch trap, and a oversized 3 inch flush valve.

Like many of the others listed above, it utilizes 1.28 gallons of water, which can save up to twenty percent more in comparison to products using 1.6 gallons.

Other things to consider

Rough in - The term rough in may be something you've come across while shopping. While it may seem complex, it's just a way for companies and consumers alike can ensure their toilet fits their waste outlet.

A rough in measuring twelve inches tends to be the most common, but there are still plenty of bathrooms that require both ten and fourteen inches. That's why it's important to measure this before you buy anything.

To find out what yours is, simply measure from from the wall to the center of your flange. Keep in mind this should be from a finished wall. You should also have fifteen inches minimum clearence from other walls to the side, or even cabinets and sinks.

Bowl - The bowl is such an important part of any toilet. It determines how comfortable one is while seated, ease of access, and how much floor space it takes up. You'll need to decide whether a standard or chair height bowl is right for you, as well as elongated or round shaped.

In terms of how a bathroom looks, the bowl can be very important. Apart from matching the color theme, you've got the choice of hiding the trapway through skirting. This can make a big difference visually.

Tank - A few specs to keep an eye on in regards to the tank. The first is the type of activation being used. Typically this will be a trip lever or a button. For dual flush models, it will have a button divided into two usually. However, there are some less common methods of activation like those that are completely hands free and utilize infrared sensors to operate the flush. A great option for germaphobes.

You also get to pick between a tank using pressure or gravity to flush out waste. The advantages of using gravity units is that they're quieter and easier to fix and find parts for. However, compressed air pressure based products are usually more efficient and have more power.

You can also purchase what's affectionately known as a prison toilet sink combo. These are basins that sit on top of the tank, in place of the tanks lid, where people can use less to wash their hands.

Mount - A decision needs to made between the traditional, floor mounted route, or wall hung, with the tank being put inside the wall via a carrier system.

A unit that's mounted to the floor would be a great option for those of you wanting to save time and installation costs. Also, if you already have a outlet going through the floor from a previous installation, this would also be a smart choice.

Those of you shopping for something that's easy to clean with all the sides easily accessible, wall mounts could meet your requirements. They are arguably more aesthetic too, due to them having a minimalistic feel.

Outlet - Where is your waste outlet located? The wide majority of homes will need to buy something with a outlet that goes through the floor. However, this shouldn't be assumed as some consumers will need a unit with a rear outlet that sends waste through the back.

Brand - We're not short of buying guides for the different brands in this industry, why not read our thoughts and opinions on WoodBridge, Mansfield, Niagara, Icera, Mirabelle, Duravit, Ove, Delta, Toto, Kohler, and American Standard to start with. We've looked at the manufacturers as a whole, and also individual product lines to help readers understand what features they may benefit from. Check the menu at the top for a full list of companies we've covered.

Consumer reports - Reading customer reviews around the web is a great way to keep yourself updated and aware of any performance issues that can arise. There are plenty of resources online to get this information. Big online shops are one, but there are also plenty of forums that specialize in consumer advice too. Don't just look for the strengths in a product, see what people are complaining about too.


The products we've chosen above are some of the most efficient toilets on the market. Not only do they have a much lower GPF rate than standard 5.0, 3.5, and 1.6 tanks, they can also help you economically. However, despite them meeting a key part of our research criteria, your own due dilligence should not stop there. We advise you to go through the specifications and see if the bowl style, tank, flush activation, and design meets your families needs.