What does GPF mean on a toilet? (Choose the right GPF toilet)

What is GPF in toilets?

The GPF of the toilet nowadays is considered one of the most vital attributes as it is directly concomitant to the consumption of water. Every toilet uses a definitive quantity of water to flush away all the waste. And GPF has the elaborated form of “Gallon per Flush.” And it denotes how much water the toilet uses per flush to evacuate waste down to the trapways. Nowadays, most water-efficient toilets use 1.28 GPF of water which is quite lower than the older conventional toilets.

How do you determine the GPF for a toilet?

It is not that difficult to measure the actual GPF of the toilet. If you take off the lid, you can see the printed mark that may look like, for example, “1.6 GPF/6.0 LPF” then your toilet uses 1.6 GPF of water per flush. If there are no printed marks, then there are other ways to determine the GPF. 

Take a compact measuring tape and put the ending portion into the toilet tank to mark the actual water level. After marking the tank water level, flush the toilet and empty the tank. Though you flush the toilet at the bottom of the tank, some water that can not be eradicated will be left. Then subtract the two values to find out the real water level. Then evaluate the length and width of the tank and multiply the height by the length by the width to find out the real volume of water. That value will be calculated in cubic inches. If you want to get the value in the gallon, then divide the result by 231, and the final result is the anticipated volume of water that the toilet uses in GPF.

What is a good GPF for a toilet?

Good GPF is a standard measurement of how much water is needed to flush the waste. Generally, the 1.6-gallon flush is considered a good GPF for a toilet, and more advanced toilets use less than this, like it uses 1.28 GPF of water to remove more than 1,000 grams of waste.

What does 1.28 GPF mean in a toilet?

1.28 GPF means your toilet uses the most efficient WaterSense technology that consumes only 1.28 gallons or 4.8 liters of water to sweep away more than 2.2 pounds of solid waste or more than 1,000 grams of solid waste.1.28 GPF toilet

Do 1.28 GPF toilets work?

It is a proven technology that is incorporated with the WaterSense technology that uses the least amount of water to dump the waste through the trapways. In today’s world, where we often face a shortage of pure water, a technology saving a huge amount of water is really a remarkable invention. According to some experts, the 1.28 GPF toilets work more efficiently than conventional toilets because these toilets have a strong 360-degree tornado flushing system that almost sweeps away all the waste without having any skid marks left.

What does 1.6 GPF mean in a toilet?

1.6 GPF means the toilet’s water consumption is almost 1.6 gallons or 6 liters of water in every flush. These toilets are called water-efficient toilets. These types of toilets can save gallons of water per year.

Can you buy a 1.6 GPF toilet in California?

It is illegal to use a 1.6 GPF toilet in California because the government has passed a rule that the public must use less than 1.28 GPF toilets in their home. This lawsuit has been activated because this region has an extreme water deficiency.

Can I buy a 1.6 GPF toilet in Texas?

Texas is where there is always a water shortage, and they are always searching for products that use less water. A mandate has been carried out where it is said that using the 1.6 GPF toilet is not legal anymore. People are allowed to use 1.28 GPF or less than that of toilets to save water consumption. So at present, you cannot buy or use the 1.6 GPF toilet in Texas. 

Can you make the toilet 1.28 GPF to 1.6 GPF?

Yes, it is possible to increase the GPF of the toilet. You need to follow some special methods to perform the conversion of the GPF. Here I am sharing some strategies for increasing the GPF of the toilet, 

  • You can uplift the tank’s float so that it can enter more water into the bowl and initiate a string flushing. 
  • You can use chemicals to clean the flush valve. After the cleaning is done, it tends to initiate a more regular flush. By using this hack, you can convert 1.28 GPF to 1.6 GPF toilets.
  • Improve the power of the cylinder float by Turning the screw clockwise to raise it. All these strategies might level up the GPF from 1.28 GPF to 1.6 GPF.

Modern/smart toilets use 0.8-1.0 gallons per flush

The intelligent dual toilets use only 1 GPF of water to remove the solid waste and 0.8 GPF to sweep away the liquid waste. This toilet model saves more than 11.5 gallons of water a day and billions of water worldwide per year. These smart toilets are approved by the WaterSense, CALgreen, and CEC requirements, and they also meet these requirements. smart toilet

How many GPF are old toilets?

Household and commercial toilets made between 1980 and 1992 use mostly 2.5 to 3.6 gallons of water. That means a single user uses more than 20 gallons of water daily. A toilet manufactured before 1980 tends to use 5 to 8 gallons, suggesting that a user consumes more than 50 gallons of water per day.  

Where to buy a 3.5 GPF toilet?

In the modern world, the demand for water-saving toilets is rising, but still, some people search for a bulk GPF toilet as they believe it prevents cloggings and unwanted skid marks. You can manually buy these toilets at your nearest hardware shop or find them on renowned online platforms like Amazon, Walmart, eBay, Wayfair, Plumber’s Choice, and many more.

How to increase GPF on the toilet?

There are some unconventional ways of increasing the GPF of the toilets, such as,

  • Repairing and upgrading the flush valve 
  • Change the toilet’s flapper and let water enter the bowl by increasing the GPF.
  • Readjusting the cylinder float so upgrade the GPF
  • Clean the clogs and increase the dimension of the trapways to increase the GPF of the toilet.

Conclusion: What GPF toilet should I get?

You should always select the type of toilet that uses less water, and to satisfy that aspect, you must choose the 1.28 GPF over the 1.6 GPF. The cause is simple. 1.28 GPF toilets are WaterSense certified, and most work on the pressure-assisted system. The tornado 360 flushing system has also been incorporated into those toilets. So in our opinion, the most worth picking for your home toilet will be the 1.28 GPF toilet.


  • What does LPF mean on toilets?

The meaning of the LPF is similar to the GPF. LPF means “Liter per Flush.” It demonstrates the amount of water a toilet uses in every flush and is calculated in liters.

  • Can the GPF be changed by replacing toilet parts?

Yes, it is possible. If you elevate the Tank Float, adjust the cylinder float, extend the flush holes, and upgrade the flush valves, then you will be able to change the GPF of that toilet. Using these techniques, you can upgrade a toilet to 1.6 GPF from 1.28 GPF.

Hi, this is Robert Crossan, the owner of this website, has 17 years of experience in the installation, maintenance, and repair of toilets and plumbing systems. After completing the Level 2 Basic Plumbing course in 2005, I started working in both domestic and commercial buildings as a professional plumber. So I can figure out the core difference between different toilet models and brands. It also helped me monitor their work performance and setbacks.

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