1.28 VS 1.6 GPF Kohler Toilets | Pros,Cons & Differences

Most toilets look the same when it comes to appearance, but choosing (the proper toilet for your sweet home) is difficult.

There are so many factors to analyze, such as 1.28 VS 1.6 GPF toilet (Kohler, Toto, Woodbridge, etc.), (elongated VS round), gravity flush VS power assist toilet, (one piece vs two piece toilet) and so on.

Do you know? Toilets used more than 7 gallons of water per flush in the 1990s. But modern bathrooms have advanced features that save $1,000 and are environmentally friendly.

So, the point is which one is better, 1.6 GPF or 1.28 GPF?

Some homeowners believe that 1.6 GPF used more water. So it’s a good flushing toilet, but the fact is that the flushing system isn’t just about using water; it also dependent on the trapway, flapper, and most importantly, the flushing mechanism.

Both flushing GPF has their own advantages and disadvantages that we will tell you in the letter section.

But if you are in a rush, then here is our one-line answer.

1.28 VS 1.6 GPF Kohler toilet means the Kohler toilet using 1.6 gallons of water in a single flush, and 1.28 GPF means the Kohler toilet using 1.28 gallons of water in an individual flush. The 1.6 GPF Kohler toilets require more water and so flush more effectively compare to 1.28 GPF toilets. They clear all the waste in a single flush.

This section will tell you whether 1.6 GPF or 1.28 GPF is better depending on the particular scenarios. We will eventually suggest the best GPF toilets based on your condition and your washroom area.

For your best understanding, I am going to start from the basics.

What is GPF in toilets:

The complete form of GPF is Gallons Per Flush. It means the amount of water used by a toilet when it is flushed.

Many people overlook this feature, but it can save you a lot of money.

The GPF gained popularity after the United States government published a rule for the benefit of the environment in the 1990s.

The rules limit the amount of water used in the toilet; the maximum amount of water per flush is 1.6 GPF.
Some states in the United States have also imposed water-use restrictions (1.6 GPF).

Choosing the right GPF is always favorable because it can save you a lot of money.

Otherwise, I can tell you to flush your dollar down the toilet.

If you don’t want to wash your money, read the next section carefully and understand your requirement.

Okay, so which one is better for toilets, 1.28 or 1.6 gpf of toilets?

1.28 VS 1.6 GPF Kohler toilets Comparisons:

Topic1.28 GPF1.6 GPF
Water using Per flush1.28 1.6
Powerful flushNoYes
Laws on the USAAll states allowSome states restricted in the USA
Area sizeSmallerLarger
WaterSense certifiedYesYes
After flush cleaningCleanClean from every corner
Flush needed during heavy useSometimes need two flushOne flush is enough
Bowl sizeSmallerLarger
PerformanceSuper SaverSuper Flush
Ideal forPerfect for a small family (4 members)Ideal for larger family

Before I go into the pros and cons of both toilets, you should know what kind of toilets we want in our house.

Type of Toilets depends on flushing system:
Nowadays, mainly three types of flushing systems are famous in our country.

Gravity flush toilets:

Toilets, in this case, use gravity to flush. The mechanism uses the weight of the water to force it into the bowl.

This toilet is used in the majority of homes in the United States.

Pressure assist toilets:

The pressure assists toilets in using air to generate more power for the flush. This is one of the fantastic technology that saves our environment in various ways.

If you are frustrated with clogging and want a powerful flushing system, then go with these best pressure-assist toilets.

Dual flush toilets:

When it comes to saving water, we all love dual flush toilets because they have two options: one for liquid flush, which uses 0.8 GPF, and another for solid flush, which uses 1.28 or 1.6 GPF.

I think you are now puzzled by the difference between 1.28 and 1.6 GPF, Right?

And I am thinking about which one is best for me?

Okay, check the following points and clear all your doubts.

What does 1.28 GPF Toilet mean?

Modern technology is producing toilets that use the least amount of water possible, and yes, the bathrooms are performing admirably.

1.28 GPF saves your water bill compare to 1.6 GPF. For your better understanding, can I share some mathematical equations?


On average, people use the toilet five times per day. So you use 1.28 * 5=6.4 gallons of water per day and 6.4*365=2336 gallons of water in a year.

In the case of 1.6 GPF toilets, you will use 1.65=8 gallons of water per day, for a total of 8365=2920 gallons of water in a year.

So, you will save 584 gallons of water per person per year, and if your family has four members, you will save 584*4=2336 gallons of water.

You can now see how much money you will save on your water bill if you use 1.28 GPF toilets.


  • Using minimum water
  • Watersense certified
  • Space saver
  • Save money in the long run
  • All USA states approved
  • Environmentally friendly
  • Flushing sound also quiet


  • Sometimes need double flush for proper cleaning
  • Smaller in shape
  • Flushing is not too strong

What does 1.6 GPF Toilets means?

As previously stated, 1.6 GPF toilets use more water than 1.28 GPF toilets.

But, to be honest, if your family relies on a single toilet and will use it frequently, try to go with 1.6 GPF toilets.

If you use a small 1.28 GPF toilet, you will need to double flush more often and use more water than 1.6 GPF toilets.

So, if you have a small family and already have a toilet and are looking for a second one, I recommend that you go with 1.28 GPF toilets or dual flush toilets.

If your family has more than four members, choose 1.6 GPF toilets because they have a more powerful flush that cleans all of your waste in a single flush.


  • Using 1.6 gallons of water
  • Powerful flush
  • No need to double flush for cleaning
  • All corners are cleaned after flush


  • Not certified by WaterSense
  • A little bit of noisy flush
  • Not approved I all states of the USA
  • Larger in size
  • Not suitable for tiny bathroom
  • No so much ecofriendly

I think you now have a clear idea of which is better for your home; simply choose it based on your requirements.

However, if you choose 1.6 GPF toilets, you must ensure that your state allows toilets that are not WaterSense certified.

What are WaterSense certified toilets?

If you want to examine the product’s worth, look at the label to see if it’s WaterSense certified or not. Your toilet must use less than 1.6 gallons of water with a high-performance flush to qualify for this certificate.

The EPA (Environmental Protection Agency) tests each toilet individually. If they pass the criteria, they are awarded the WaterSense certificate.


Q1. Best Kohler 1.28 GPF toilets:

If you want a one-piece 1.28 GPF toilet, consider the (Kohler Cimarron) or (the Kohler Santa Rosa.)

Q2. Does Kohler offer a 1.6 GPF toilet?

Yes, Kohler has a 1.6 GPF elongated two-piece toilet that is Kohler well-worth K-3978-T.

Q3. What is the best Toto 1.28 Gpf toilet?

After doing lots of analysis, I can say, Toto Drake 2 is the best Kohler 1.28 GPF toilet.

Q4. What is the best Toto 1.6 GPF toilet?

TOTO CST744SL Drake’s non-clogging toilet is the best 1.6 GPF toilet. That will change your bathroom experience.

Q5. Is a dual flush toilet worth it?

Yes, it can save lots of water bills and also eco-friendly. You have two options for solid and liquid purposes. The technology is perfect for modern days.

Q6. Which states require you to purchase toilets with a GPF of less than 1.6?

The rules you have to maintain if you are staying this USA states,
New York

Q7. Is a 1.28 flush enough?

If your haven has more than one unit and wants an extra toilet for water-saving, then a 1.28 flush is enough for your house.

Wrap on 1.28 VS 1.6 gpf Kohler toilets and others also

There is no discernible difference in appearance; all of the difference is internal between 1.28 and 1.6 GPF toilets.

If you go to any of the following brands: Kohler, Toto, American Standard, and so on. When it comes to this point, all of the toilets have the exact differences.

So, choose based on your requirements. For example, if you want to save more water, choose 1.28 GPF toilets, ideal if your family is small.

If you want a powerful flush, choose 1.6 GPF toilets to flush all waste down in a single flush.

Remember that not all 1.6 GPF toilets flush well because flush power is determined not only by water consumption but also by the flush valve, trapway, and flushing mechanism.

Some states restrict the use of toilet flushes. In that case, you have no choice but to use a 1.28 flush. In addition, you can check dual flush toilets, which are both water-efficient and have a powerful flush.

Before purchasing a toilet, consider not only the water consumption but also the material quality, price, bowl size, and not forget to check rough-in size.

If your bathrooms are small in size then most probably (the rough-in is 10 inches). Double-check it before buying any toilet.

If you have any questions regarding 1.28 VS 1.6 GPF toilets, then comment to us.

That’s all for today.

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