How to Measure for a Toilet Replacement
Last updated September 7, 2023
Toilets can last a long time in your home, experts say up to 50 years if they’re properly installed and gently operated. However, you can replace a toilet at any time. Modern toilets have features that you may want in your renovated bathroom.
The first step to replace a toilet in your home is to measure the space and make sure you bring the right toilet home.
In this guide, you’ll learn how to measure for a toilet replacement.
For accurate measurements, use a standard cased tape measure, pencil and paper.
Difficulty:
Beginner
Duration:
Under 2 hours
Table of Contents
Standard Dimensions of a Toilet
Tank Height
Bowl Shape
Rough-In Dimensions
Standard Dimensions of a Toilet
Before you shop for a new toilet, determine how much room you need to install a new toilet. The most important of these measurements is the distance between the floor drain and the wall, called the rough-in. The standard rough-in dimensions for toilets is 12 inches. In older homes or small bathrooms, you’ll sometimes see rough-in dimensions of 10 inches or 14 inches.
Determine your bathroom's rough-in by measuring from the wall behind the toilet to the middle of the bolts on the base of the toilet.
Tank Height
Tank height is an important dimension of a toilet. Measure toilet tank height from the floor to the top of the rim. Whether it's marketed as "chair height," "comfort height," or "tall height," the best toilets to buy for your bathroom should have a rim height that makes it easy to sit down and stand up.
Standard-height rims are 14 to 15 inches from the floor and should work well for shorter people. If you’re taller, consider chair height toilets that have a toilet seat height of 17 inches or more.
Tip: ADA compliant toilets meet the standards of the Americans with Disabilities Act and have a rim height of 15 to 17 inches.
Bowl Shape
You’ll need to measure from the rear wall to help determine the best toilet bowl shape for your space, since the dimensions of a toilet bowl will differ based on their shape.
Difference between an elongated toilet and a round toilet:
- Elongated toilet bowls measure up to 31 inches from the wall behind the toilet to the front of the bowl. Elongated bowls provide greater comfort while seated.
- Round toilet bowls extend up to 28 inches from the wall.
Rough-In Dimensions
Rough-in dimensions are smaller in older homes. The standard size for modern homes is 12 inches, while older home rough-in dimensions are usually 10 inches.
Toilet rough-in dimensions:
- Supply line (vertical): 8 1/4 inches
- Supply line (horizontal): 6 inches to either side
- Discharge/drain hole from back wall: 12 1/2 inches
- Discharge/drain hole from back wall (vertical): 0, drain is at floor height
- Fixture (side to side): 15 to 18 inches clearance from wall, sink or other fixture
- Fixture (front): 30 inches is recommended
The first step to getting the right toilet is to learn how to measure for a toilet replacement. Ready to find the right toilet for you? Use The Home Depot Mobile App to locate products and check inventory. Once you’ve found a toilet you love, we offer professional toilet installation services to get it into your bathroom quickly and easily.
