1.6 gpf vs 1.28 gpf. What Is The Difference?

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Last Updated on August 8, 2022 by acechapman

Toilet performance has improved over the years as toilet technology has advanced. Water efficiency per flush is one of the most significant improvements. Modern low-flow toilets require less water to flush than traditional toilets.

But is too much water really better than too little? Is it better to use 1.28 GPF toilets than 1.6GPF toilets? We will compare 1.28 GPF and 1.6 GPF toilets in this article. This will allow us to determine which low-flow toilet is best.

What is GPF?

GPF is the amount of water required to flush a toilet. This is a vital aspect of a toilet. Toilets older than modern have a higher GPF, which makes them less wasteful and more environmentally friendly.

While water conservation is important, it is also about saving money. A toilet that uses too much GPF is wasting money and flushing out dollars.

As a way to conserve water, the Energy Policy Act has been in effect since 1992. Toilets sold in the United States after January 1994 must use no more than 1.6 GPF. Low flush toilets with 1.6 GPF became the industry standard with that maximum in place.

The GPF that a toilet needs to function has fallen from 7 GPF to a shocking 3.5 GPF, then to 1.6 GPF over the years. In recent years, however, the demand has increased for a lower GPF. 1.28 GPF toilets are now available and have been growing in popularity among households.

High-efficiency toilets are cost-effective and can save water. It is possible to save up to 20.000 gallons of water per year by using 1.6 GPF flow toilets. High-efficiency toilets such as these have cut water consumption by 50%. These statistics add up and the advancements in 1.28 GPF toilets will continue to improve the stats.

1.6 gpf vs 1.28 gpf

What does GPF have to do with a toilet’s overall performance?

There are many factors to consider when evaluating the performance of a toilet. These include: Is it loudly flushing, how often it clogs, and how powerful it flushes. These features depend on whether the toilet is pressure-assisted or gravity-fed.

Gravity models use gravity to dispose of waste. These models are usually equipped with enhanced water velocity technology to siphon the waste downhill. To propel waste at a faster rate, the pressure-assisted base has front jets. These toilets are much noisier than traditional gravity-based toilets.

Modern advancements in toilet technology are making it possible to make a low-flow toilet that saves water and still delivers excellent performance. Low-flow toilets may not be as powerful as those with higher GPFs. This is a common misconception.

The 1.28/1.6 GPF toilets break this mold, as they use less water. Low-flow toilets are more efficient. To reduce the need to flush twice, toilet manufacturers have created newer models that use less water.

In the beginning, high-efficiency toilets were thought to be more clogged than higher GPF toilets. However, this has changed in recent years. Low-flow toilets should be economical and environmentally friendly. Today’s designs focus on eliminating double flushes.

Double flushing means that more water is wasted and more money goes down the drain. The toilet industry has made low-flush toilets more efficient over the last two decades and people have changed their attitudes towards them.

1.28 GPF Pros & Cons


  • A flush requires only 1.28 gallons.
  • Quieter than other toilets
  • Eco-friendly
  • Money saving
  • A smaller toilet bowl that saves space
  • All states in the United States allow this model
  • Based on an average of 5 flushes per day, an estimate of 2,336 gallons per year is used by each person.


  • Low-powered flush
  • You may need to flush more than once

Pros and cons of 1.6 GPF


  • A flush requires only 1.6 gallons
  • Typically quiet
  • One flush needed
  • Flushing power


  • Overall, it is not as efficient as a 1.28 GPF
  • Unlike the 1.28 GPF, it is not as eco-friendly
  • Bulky design with a bigger tank
  • This type of toilet is not permitted in all US states.
  • Based on an average of five flushes per day, an estimate of 2,920 gallons per year is used by each person.

What is a WaterSense Certified Toto?

A WaterSense certified sticker ensures that a high-quality toilet has been tested to ensure it meets high standards and is water efficient. To be eligible for a WaterSense Certified label, toilets must consume less than 1.6 GPF. These toilets have been independently tested and are certified by the EPA (Environmental Protection Agency).

Although they are most commonly found in residential properties, their superior overall performance is making them more popular for commercial use.

What is the best GPF for a toilet?

Comparing 1.28 GPF toilets to 1.6 GPF toilets shows that they are very similar in function, but each has its own advantages and disadvantages. In general, 1.28 GPF toilets are becoming more popular in recent years. The world is becoming more conscious of the environment, and society is trying to do its best for the environment as well as its pockets.

Another question is: Are 1.6 GPF toilets sufficient? It can be for some families. Although it is losing popularity in households, many are still sticking with this model. It may be because it has a stronger flush, so people assume that it will perform better. There is a tradeoff. To have more power it will use more water.

Dual flush toilets – A better alternative to 1.28 GPF or 1.6 GPF toilets

You might want a dual flush toilet. Dual flush toilets allow you to choose between a full or half flush. A half flush can be used for liquid waste and can be as low as 0.8 GPF. A full flush is recommended for solid waste. A full flush may take as little as 1.28 GPF.

Dual flush toilets also have lower water consumption rates than single flush toilets (1.28 GPF or 1.6 GPF). This can be explained in part by half-flushes replacing full flushes with liquid waste and also because the average flush uses less water.

Although a dual flush toilet may be more costly upfront, it will pay off in the long term. You will not only save money on your water bills but also conserve water, which is vital for the environment.

Dual-flush toilets can be found in all 50 states, including Texas, California, and Colorado. Dual flush toilets are WaterSense certified and widely available. Dual flush toilets have two buttons at the top of the tank lid, instead of the traditional flush handle.

Can 1.6 GPF toilets be purchased in Texas and California?

1.6 gpf vs 1.28 gpf

As we mentioned, not all states permit the use of 1.6 GPF toilets. California and Texas, for example, prohibit this type of toilet. Why? The highest indoor water use in the country is in toilet water, at more than 30%.

High water wastage can be a concern in states like Texas and California, which are both prone to droughts. California was the first to implement this rule, and Texas soon followed suit. It was a way to save water, and it helped states become more environmentally conscious.

As you can see, both 1.28 GPF and 1.6 GPF toilets have their pros and cons. They are both water efficient, and there are many options. Which one should you choose? This will depend on how efficient your toilet is in terms of water efficiency and how willing you are to sacrifice some power to get 1.6 GPF toilets.

You may not be able to choose depending on where you live. The maximum toilet flush allowed for a toilet purchased in California, Texas, Georgia, or New York is 1.28 GPF.

If you don’t live in one of these states, but still want to have more water and power, then a toilet with 1.6 GPF will work better for you.


You should consider the following factors when buying a new toilet: flushing power, performance, efficiency, and cost.

There are so many options for toilet brands and types available that it can be difficult to decide which one is right for you. It is important to consider the GPF of your toilet.

Although the 1.28 GPF and 1.6GPF toilets may look similar, they use less water which can be advantageous depending on where you live and your lifestyle.

A 1.28 GPF toilet will work better if you live in an area where water consumption is limited and the environment comes first. If you prefer your toilets to be powerful and are willing to use a little more water from time to time, then a 1.6 GPF toilet is the best choice.

This article should help you make an informed decision about your next toilet purchase.

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