How to Measure Toilet Rough-In

Here we teach you how to measure a toilet rough-in. This pivotal task is essential to the installation of a new toilet. Those inexperienced in plumbing may not have ever heard the term rough-in, so allow us to address that before we get started.

What Is a Toilet Rough-In?

The rough-in is the location of the water outlet (typically) beneath the toilet. The rough-in measurement is the distance from the center of the outlet to the wall facing the back of the toilet. The standard is a 12” rough-in, but you will find alternatives, and in those cases, you are likely facing a 10” or 14” rough-in measurement.

How to Take a Toilet Rough-In Measurement

The general rule of thumb for clearance from the wall that faces the bowl is 24" and just about 15" on each side. The rough-in measurement indicates how much clearance you have and will allow you to select a compatible toilet.

There are a few common errors when it comes to measuring a toilet rough-in. You will want to be sure to avoid these pitfalls:

Many make the mistake of measuring from the baseboard that you often find along the perimeter of a bathroom floor. In some cases, this may skew your measurement by up to ½”.
Do not measure to the bolt cap on the base of the toilet. Many wrongly guess that the bolt cap is aligned with the center of the outlet hole, but that is not a safe bet.
Many think that bigger units, like ADA-approved and elongated toilets need a larger rough-in. Avoid this pitfall, because it’s not always accurate. There are elongated toilets built to fit a 10” rough-in, and some are built to fit 14”.

Good Luck with Your Project!

When you measure the distance from the toilet to the wall, let us know how your project goes on social media. Share pictures with your install and tag us. Please post comments and questions about how to measure a toilet rough-in. Let us know how we can answer more of your DIY questions. Thanks for visiting PlumbersStock.

Lastly, don't forget to update your installation with us when you need replacement toilet parts. Also, if you're looking for an innovative way to improve your hygiene bathroom experience, consider electronic bidet seats for your toilet.