Difference between 10 and 12 rough in toilet | Detail Guide

Toilet rough-in is one of the most important parameters while buying a new toilet for home, office, or elsewhere. 

The Rough-in determines the distance between the wall and the flange center.

Toilet rough-in are coming four types 14”, 12”, 10” and 8” rough-in toilets. It’s easy to measure the rough-in; just follow a few basic steps.

What is a 10 inch Rough In the Toilet?

When you wonder about ‘what a 10-inch rough-in toilet means’, it refers to the finished wall and the floor flange opening center distance of about 10-inches.

10-inch rough-in is usually found in the old models’ homes. Although, there are only fewer toilets options available.

If you’re renovating your toilet and found out that it is a 10-inch rough-in, don’t worry about just buying the best 10-inch rough-in toilet.

10-inch Rough-in Toilet Advantages and Disadvantages

Advantages of 10-inch Rough-in Toilets

  • Save a lot of space
  • A great option for a smaller bathroom
  • Ideal for kids, pets
  • Later you can change 10 inches to 12-inch rough-in

Disadvantages of 10-inch Rough-in Toilets

  • Expensive
  • Less variation option
  • More prone to clog
  • As the water closet is attached to the wall, in humid area-the tank increase sweating, damp and mold growth

What is 12-inch Rough-in Toilet?

When you query about ‘what a 12-inch rough-in toilet means’, it refers to the finished wall and the floor flange opening center gap of about 12-inches.

Nowadays, 12-inch rough-in toilets have become standard and have more variations.

12-Inch Rough-in Advantages and Disadvantages

Advantages of 12-inch rough-in

  • Less prone clog
  • Increase flushing power
  • Ideal for everyone
  • Fits into small to large laboratories
  • Lots of toilet options
  • No damp or sweat tank


  • You can’t replace a toilet from a 12 to a 10-inch toilet.

What is the Difference Between 10 and 12 Rough in Toilet?

You can see the difference between 10 and 12 rough-in toilets from the above description. How many pros and cons of them, etc.

The first point first, 10 VS 12 rough-in a toilet is about the measurement from the wall to the center of the flange.

12-inch rough-in refers to the standard rough-in size, where 10 inches only found the old model house.

10-inch toilets have fewer options to choose from. Thanks to 12-inch, we have more options from one-piece to a two-piece, round to elongatedchair to standard height along with water-efficient performance.

10-inch rough-in toilets have a more prone clogging issue, whereas 12″ rough-in is remembered as the best for no-clog toilets.

If you live in humid regions, then 10-inch rough-in is going to be a mess for you because they are prone to damp and mold growth. But not in 12” rough-in.

As 10″ rough-ins are old model toilets, they consume about 1.6 GPF of water each flush. Thanks to the new era of 12″, they only utilize 1 to 1.28 GPF of water. 

See the water consumption value of 1 to 1.6 GPF of water. 

Calculate average water consumed by 2 members in one house, use once the toilet then how much water will waste.

1 Gallons = ~4.55 liters
If the 2 members in a house flush the toilet, then 2 x 4.55 = 9.1 liters means 2 Gallons per Day.

In the whole year, 365 x 9.1 = 3321.5 liters of water means ~730.63 gallons of water per year will consume.

1.28 GPF = ~5.81 liters. For 2 members 2x 5.81 = 11.62 liters = ~2.55 Gallons of water per Day.

In the whole year, 365 x 11.62 = 4241.3 liters of water means =~932.96 Gallons of water per year.

For, 1.6 GPF = ~ 7.28 liters water . For 2 member 2 x 7.28= 14.56 liters =~ 3.20 Gallons of water per Day.

In the whole yera, 365 x 14.56 = 5314.4 liters = ~ 1169.00 Gallons of water per Year.

In the end, if you use 1.28 GPF, you can save up to ( 5314.4 – 4241.3) = 1073.1 liters =~ 236.1 Gallons per water per year. 
You may assume the different water bill also.

If I describe availability, then from now to the future, the only toilets are available in countries that consume 1.28, not more than that. Which already become regulation in California Energy Commission and CALGreen.

So, if you are willing to buy 10” rough-in, see the advantage and disadvantages. But don’t panic about what to do having a 10-inch already.

Should you exclude the toilet or something else, I have a solution for you. As I previously mentioned, a 10” rough-in toilet can transfer a 12” rough-in.

The process is so simple.

Can You Replace a 10-inch Rough-in Toilet with a 12-inch Rough Toilet?

Yes, you can in various ways. 10 inch to 12-inch means there is a 2” gap between the rare toilet wall and the drain outlet center. That’s not exactly the effect of flushing.

If really you want to replace a 10-inch Rough-in Toilet with a 12-inch Rough Toilet use Offset Flange.

A flange is a connector between the toilet flush outlet to the main drainpipe. It should install above ¼ inch from the floor to press down hard on the wax ring and create a tight seal for the toilet.

An offset Flange refers to an adaptor to install or transfer between rough-in without damaging the floor. Also, you can change the direction as well.

How to install an Offset Flange

  • Measure the size of the drain opener, either 3” or 4” wide
  • Buy your desired size of Offset Flange, available 10 to 14” and wax ring to tight seal and bolts
  • Turn off all water supply lines that connect to the particular figure
  • Flush completely and sponge out the remaining water to remove the tank lid
  • Now take an old cloth/ towel
  • Carefully remove your old toilet and place it on the cloth
  • Now remove the old wax ring, clear the place around the base area
  • Now place the new Offset Flange instead of the old one
  • Place the wax ring and then attach the bolts with the toilet
  • Then connect the water line and turn them on
  • After filling the toilet tank, flush once so check whether any leakage happens or not.

Best Offset Flange

Oatey 43500 Level-Fit Offset Toilet Flange

Difference between 10 and 12 rough in toilet | Detail GuideDifference between 10 and 12 rough in toilet | Detail Guide

PlumBest C54402 PVC Offset Closet Flange

Difference between 10 and 12 rough in toilet | Detail GuideDifference between 10 and 12 rough in toilet | Detail Guide

How Do I Know my Toilet is a 10 or 12 Rough-in

As I mentioned earlier, rough-in determines the gap between the rare wall of the toilet and the center of the flange or drain opener.

Just follow below simple steps, and you’ll be able to know whether the toilet is 10” or 12” rough-in

Before that, you need a measuring tape.

Floor Mounted

  1. Measure the drain opener first and determine its center point and mark beside that
  2. Take the measuring tape measure from the wall to the bolt caps present at the base of the toilet, which allows the seal or tightening of the whole system.
  3. If you have more than one or two caps, always take rare bolts for rough-in measurement
  4. While you’re measuring a stud wall, don’t forget to include the width of the solid wall

Corner toilet

  1. To start, stretch the tape by both angles of the toilet to the middle of the bolt caps to note the exact locations
  2. Draw perpendiculars from both points
  3. The rough-in is where both points overlap each other.

Conclusion 10 VS 12-inch Rough-in Toilet

There will be four different sorts of toilet rough-ins. Toilet rough-in sizes include 14″, 12″, 10″, and 8″. Toilet rough-in is one of the most critical factors to consider. 

The key point to make is that 10 VS 12 rough-in a toilet refers to the distance from the wall to the center of the flange. Hope you can measure all those points and get your best rough-in toilet.

Is 12-inch rough-in standard for toilets?

No, there is no standard for toilet rough-in size. The most common rough-in size for toilets is 10 or 12 inches, but there are also toilets with 8-inch or 14-inch rough-ins.

Toilet manufacturers make toilets to fit a variety of different rough-in sizes so that everyone can find a toilet that will fit their bathroom.

When you’re shopping for a toilet, make sure to check the rough-in size that the toilet needs. That way, you can be sure that the toilet will fit in your bathroom. If you’re not sure what size rough-in your bathroom has, you can measure it yourself or ask a professional to help you out.

Leave a Comment