The most popular toilet models on the market are 1.28 GPF and 1.6 GPF toilets. “GPF” stands for gallons per flush.
1.28 GPF toilets use less water than 1.6 toilets and are more energy-efficient. However, 1.6 GPF toilets have a more powerful flush that reduces the risk of clogs and keeps the toilet bowl cleaner for longer. 1.28 GPF toilets are more expensive to purchase, with an average price of $280.00. Due to their high efficiency, 1.28 toilets save money in the long term on energy and water bills. In comparison, 1.6 GPF toilets will cost more on your utility bill but are available to purchase for as little as $120.00.
There are pros and cons to both models of toilets. This article breaks down the positives and negatives of 1.28 GPF and 1.6 GPF toilets so you can make an informed decision before buying your next toilet.
What is a 1.28 GPF Toilet?
1.28 GPF toilets use a small amount of water. They use 1.28 gallons per flush making them one of the most eco-friendly, energy-efficient toilets on the market. 1.28 GPF toilets have smaller water valves which result in less powerful flushes that require only a small amount of water.
On average, 1.28 GPF toilets use 20-25% less water than 1.6 GPF toilets. This translates to an average of 2 gallons per person of water conserved per day. Over time, the efficiency of 1.28 toilets is evident on water bills, especially in homes of large families.
States are taking legislative strides toward protecting natural resources like water. California, Texas, Georgia, and Colorado recently enforced new building codes that max toilet water usage. 1.28 GPF toilets are now the maximum-sized toilets. Other states are offering rebates for residences that purchase 1.28 GPF toilets as an incentive to install energy-efficient appliances in their homes.
Benefits of the 1.28 GPF Toilet
There are several benefits to purchasing a 1.28 GPF toilet. The most obvious is its efficiency and consequent cost savings on water bills. 1.28 GPF toilets are the best choice for those looking to reduce their carbon footprint and protect natural resources. Due to its small water valve, a 1.28 GPF toilet also produces less sound than other models on the market.
Reduced Water Use
A 1.28 GPF toilet saves up to 25% more water than a 1.6 GPF toilet. An average person will use 7 gallons of water flushing a 1.28 GPF toilet, 2 gallons less than other models. This translates to an average of 20% per year annual savings on water bills.
Reduced water usage is especially important for homes with lots of occupants. They are also beneficial in commercial spaces and high-occupancy buildings. The more people that use the toilet, is more of an opportunity to save on water.
Make sure to check if your state is participating in a 1.28 GPF toilet rebate program. Local legislatures are encouraging residents and commercial builders to install energy-efficient appliances. This will save you money on your toilet purchase. It is as simple as submitting a receipt through the rebate program offered by your state. However, the rebate is paid differently in each state.
Quiet Flush
1.28 GPF toilets only use 1.28 gallons of water per flush. The small amount of water means a small flush. This results in a quieter flush. Soft flushes are convenient for hotels and apartment buildings. It gives the user added privacy. No more waking up to the neighbor flushing their toilet at 1 AM!
Quiet flushing toilets are also helpful for families with small children. The loud “whoosh” of a 1.6 GPF toilet can be intimidating for children who are potty training. 1.28 GPF toilets also have lighter flushing mechanisms, meaning it is easier to work the toilet. This is another advantage to buying a 1.28 GPF toilet if you have children or elderly family members living with you.
Decreases Energy Bill
Energy-efficient appliances use minimal resources to operate. Purchasing a 1.28 GPF toilet will decrease your water bill significantly. A 1.28 GPF toilet will save 2 gallons of water per day per person. If a family has 6 people living in the home, that is a savings of 12 gallons per day, and 4,380 gallons per year! Imagine how much money you will save on your water bill.
Drawbacks of the 1.28 GPF Toilet
There are a few drawbacks to the 1.28 GPF toilet. The worst of them is its soft flush. The lack of power can lead to clogs. It also means you will need to clean the toilet bowl more often since the flushed water is not powerful enough to remove stains and debris.
Less Powerful Flush
The main drawback of the 1.28 GPF toilet is the possibility of clogs and plumbing issues. Because it uses less water, the flush is not as strong as a 1.6 GPF toilet. You may need to flush more than once for solid waste. Depending on how often this happens, your water savings will deteriorate quickly.
The flush of a 1.28 GPF toilet won’t clean the toilet bowl. There isn’t enough power behind the water to rinse skid marks or leftover waste from the inside of the toilet. This means your 1.28 GPF toilet may require more regular cleanings to keep the bowl sparkling white.
There is also a higher risk of serious plumbing issues with a 1.28 GPF toilet. Constant clogging can lead to bigger problems including clogged sewer lines. The light flush is not always enough to push waste and paper all the way through the plumbing. This presents a greater risk for a stopped-up toilet.
Thankfully, manufacturers have begun to come out with 1.28 GPF pressurized toilets. These models have pressure valves in the toilet tanks. This pressure helps propel the water through the toilet and pushes waste along with it. Pressure-assisted toilets are much more powerful than standard gravity-flushing toilets. Many models are available as 1.28 GPF toilets. This eliminates the issues surrounding soft flushes.
It is also important to note that 1.28 GPF toilets are more expensive to purchase than other toilets on the market. While this isn’t a serious problem considering state rebates and long-term water bill savings, it is still something to consider if you are shopping on a budget.
What is a 1.6 GPF Toilet
1.6 GPF toilets use 1.6 gallons of water per flush. They have the largest water capacity allowed for toilets in the United States. Its powerful flushing power reduces the chances of clogging and requires less regular cleaning than 1.28 GPF toilets. 1.6 GPF toilets are easily found at most hardware stores and are the least expensive style of toilet. There are also more options for ADA-compliant toilets with 1.6 GPF models.
Benefits of the 1.6 GPF Toilet
The primary benefit of 1.6 GPF toilets is their flushing power. 1.6 GPF toilets will easily flush solid waste in one go. Unlike 1.28 GPF toilets, the larger water capacity in 1.6 GPF toilets propels paper and waste through the plumbing system.
In addition, the increased amount of water in 1.6 GPF toilets rinses the toilet bowl with each flush, keeping your toilet clean longer. Not only is waste removed in one flush, but stains and marks are also wiped away.
More Powerful Flush
1.6 GPF toilets have larger water valves that allow lots of water at a higher velocity to pass through with each flush. You will probably only have to flush once with a 1.6 GPF toilet. Its strong water flow will also push through heavy waste, preventing clogs.
The powerful stream encourages whatever you send down the toilet to make it through to your sewer system. This results in fewer maintenance issues. While it uses more water, the lower risk of clogs is the reason why 1.6 GPF toilets are still popular in the hospitality, medical, and commercial real estate industries.
In some instances, the powerful flush of 1.6 GPF toilets outweighs the water savings from 1.28 GPF toilets. Because you only have to flush once, less water is used in solid waste removal.
Takes Less Time to Clean
The high water pressure in a 1.6 GPF toilet helps to clean the bowl. Water runs down the front of the toilet bowl in a steady stream with each flush. This wipes away leftover waste and stains.
The powerful flush reduces clogs which means fewer opportunities for water to overflow from the toilet. This will keep your floors clean. No need to keep a gross plunger next to a 1.6 GPF toilet!
Drawbacks of the 1.6 GPF Toilet
Purchasing a 1.6 GPF toilet has a few downsides. They are more expensive in the long run than 1.28 GPF toilets. This is because of the amount of water they use. If you have a large family, a 1.6 GPF toilet will rack up a high water bill.
In addition, 1.6 GPF toilets are not energy efficient. They pose more environmental risks and waste natural resources. A cosmetic disadvantage to 1.6 GPF toilets is that they flush very loudly.
More Expensive
The main drawback of the 1.6 GPF toilet is the amount of water that it uses. The average person will use over 9 gallons of water per day by flushing a 1.6 GPF toilet. Not only will this hurt your wallet on your water bill, but it is also detrimental to the environment. Many areas of the United States are experiencing water shortages. Using extra water to flush the toilet is not a responsible allocation of resources.
While the 1.6 GPF toilet is less expensive to purchase, it will cost you more in the long run. Your water bill will be higher than if a 1.28 GPF toilet was used. You will also miss out on State rebates by purchasing a non-energy-efficient toilet.
Louder Flush
More water means a louder flush. If you value privacy while using the bathroom, a 1.6 GPF toilet is not the answer. The powerful water makes a loud noise when it is pushed through the valve. There are no secrets in a bathroom with a 1.6 GPF toilet!
The loud “swoosh” from 1.6 GPF toilets is not just inconvenient or embarrassing. Children can be scared by loud noise. This can be discouraging for potty training.
Product Comparison
Still unsure if a 1.28 or a 1.6 GPF toilet is right for your bathroom? We outlined the main differences between each model. This will take the guesswork out of choosing the best toilet for you and your family.
| Toilet Type | Gallons per Flush | Average Water Use Per Person Per Day | Sound | Clog Risk | Average Cost |
| 1.28 GPF | 1.28 | 7 | Low | High | $280.00 |
| 1.6 GPF | 1.6 | 9 | Loud | Low | $200.00 |
Let’s look at the best-selling models of 1.28 GPF and 1.6 GPF toilets based on ratings and reviews on www.thehomedepot.com
Kohler Elmbrook Single Flush 1.28 GPF Toilet
This toilet is currently on sale for $199. The regular price is $270.00. Home Depot customers love this toilet because it is easy to install and features a “one-flush” system. It is ADA compliant and comes with a one-year warranty. The Elmbrook 1.28 toilet boasts a 4.6-star product review and is one of the top selling 1.28 GPF toilets at Home Depot. Buy the Elmbrook at Home Depot
Glacier Bay 2-Piece 1.1/1.6 GPF Toilet
The Glacier Bay 1.6 GPF toilet is an inexpensive option for those looking for a 1.6 GPF toilet. It comes with everything you need for a fast installation including the seat, wax ring, and floor bolt mounting kit.
You can buy the Glacier Bay toilet for only $119 at Home Depot. It is available in 4 colors. It has 4.4 stars and is one of the top-selling 1.6 GPF toilets on Home Depot’s website. This toilet has a push button flush instead of a handle. Buy it at Home Depot
Home improvement stores have a wide variety of toilets to choose from. Deciding on whether you want a 1.28 GPF or a 1.6 GPF toilet is a good way to narrow down the options.
1.28 GPF toilets cost more upfront, but sometimes qualify for rebates due to their high efficiency. The primary benefit of 1.28 GPF toilets is their energy efficiency. In the long term, 1.28 GPF toilets will save you thousands of dollars on your water bill.
In contrast, 1.6 GPF toilets are cheaper to purchase. Their powerful flush helps to keep the toilet bowl clean and reduces the chance of clogging. This saves you time and money on maintenance.
However, 1.6 GPF toilets are less efficient and use a significant amount more water. Toilets are a long-term investment appliance for your home. Take your time in making a decision and decide which model will best benefit your family.
Ruben has a diverse background in the home services industry, with experience running a construction company, a kitchen and bath showroom, and a moving and relocation company. This breadth of experience has provided him with a wealth of knowledge and expertise in various areas of home improvement in general and specifically in the heating and plumbing niche.