Installing a toilet was one of the first DIY projects we tackled as new homeowners back in 2006. Nearly two decades and many toilets later, the process is familiar and straightforward. It can feel intimidating at first—messy, heavy, and technical—but with the right steps and a little patience, most people can do it themselves. This guide covers replacing a toilet, fixing a leaking or rocking toilet, or reinstalling a toilet after a remodel.
Follow the steps below from planning and measuring to finishing touches. Read the full tutorial before starting and gather the necessary supplies to avoid delays mid-project.
Tools & Supplies Needed
You don’t need a lot of specialized tools to install a toilet. Here are the common items that will make the job easier and help you avoid surprises.
- New toilet (or your existing toilet if reinstalling)
- Measuring tape
- Wax ring kit (consider also an extra thick ring if your flange sits deep)
- Adjustable wrench or groove joint pliers
- Flathead screwdriver
- Spare rag
- Towels or blankets to protect fixtures
- Sponge, paper towels, or small bowl for water removal
- Utility knife
- Hacksaw
- White silicone caulk
- Level (optional)
- Work gloves (optional)
If you plan to reuse the existing toilet, a new bowl/tank isn’t necessary. Steps below include how to clean and reinstall your current unit.
Steps To Install A Toilet
Here’s a quick overview of the full process. Detailed instructions follow for each step.
- Measure the rough-in
- Choose and purchase a toilet
- Remove the old toilet
- Prepare the floor and flange
- Add the wax ring
- Place the toilet bowl
- Bolt the toilet bowl
- Install the toilet tank
- Connect the water line
- Finish the installation and caulk
Some steps can be skipped or altered when reinstalling the same toilet, but reading the full sequence is useful for troubleshooting.
Step 1: Measure Your Rough-In
The rough-in is the distance from the floor bolts to the finished wall behind the toilet. Most standard toilets use a 12″ rough-in. Measure from the center of the flange bolts to the finished wall surface, including baseboard thickness. Older homes sometimes have a 10″ rough-in and require a compact toilet designed for that size.
Confirming rough-in before buying avoids returns and compatibility issues.
Step 2: Purchase Your New Toilet
When choosing a toilet, consider shape, height, configuration, and flush options:
- Round vs. elongated bowl: Elongated bowls are usually more comfortable; round bowls work better in tight spaces.
- Comfort vs. standard height: Comfort or chair-height toilets are around 17″ to the seat, while standard models are about 14–15″.
- One-piece vs. two-piece: Two-piece toilets are lighter to maneuver during installation; one-piece models have a seamless look.
- Single vs. dual-flush: Dual-flush options save water by offering different flush volumes for liquid and solid waste.
Choose a model that fits your rough-in and personal preferences for style and comfort.
Step 3: Remove Your Old Toilet
Removing the old toilet is basically performing the installation steps in reverse. The key tasks are:
- Turn off and empty the water supply
- Disconnect the water line
- Remove the tank (on two-piece toilets)
- Unbolt and remove the bowl
- Plug the flange opening temporarily
Turn off and empty water
Shut off the valve behind the toilet by turning it clockwise. Flush to drain the tank and bowl, and use a sponge or small cup to remove remaining water.
Disconnect the water line
Loosen the nut where the supply line meets the tank. Expect a small spill and have towels or a bowl ready. You can usually leave the line attached at the wall.
Remove the tank and bowl
Remove the tank bolts and lift the tank onto a towel. Then remove the base bolts, score any caulk around the base, rock the bowl gently to break the wax seal, and lift the bowl away. Plug the flange hole with a rag to block sewer gases.
Step 4: Prepare The Floor & Flange
Clean old wax and debris from the flange with a putty knife, utility knife, or screwdriver. Remove the old flange bolts and replace them with the new bolts that come in your wax ring kit. Make sure the flange is not cracked; if it is, it should be repaired or replaced before proceeding.
If reinstalling the same toilet, clean old wax off the base as well.
Step 5: Add The Wax Ring
Place the wax ring on the underside of the toilet bowl rather than on the flange for easier, more accurate placement. If you’re unsure about flange depth or tile thickness, have both a standard and an extra-thick ring available. Press the ring lightly onto the toilet outlet so it sticks in place while you position the bowl.
Step 6: Place The Toilet Bowl
Carefully lower the bowl straight down onto the flange so the bolts pass through the base holes. Use a helper if needed. Press down firmly to compress the wax ring and form a seal. A trick that helps align bolts is temporarily placing straws over the bolts so you can see and guide the toilet onto them.
If placement goes wrong, discard the deformed wax ring and start again with a fresh one. Reusing a crushed ring risks leaks.
Step 7: Bolt The Toilet Bowl
Install washers and nuts on the flange bolts and hand-tighten. Alternate tightening each side gradually to avoid cracking the porcelain. Cut off excess bolt length with a hacksaw and snap on the plastic caps.
Step 8: Install The Toilet Tank
Position the tank onto the bowl, aligning the large rubber gasket with the hole. Install the tank bolts with rubber washers and hand-tighten, then snug carefully with a wrench and screwdriver. Tighten evenly to avoid stressing or cracking the porcelain. Check the tank sits level before final tightening.
Step 9: Connect The Water Line
Reattach the supply line to the tank and turn the shutoff valve on slowly. Let the tank and bowl fill, then flush a few times while inspecting for leaks at the supply connection, tank bolts, and around the base. Tighten minor leaks or replace washers as needed. If water appears under the bowl, the wax ring may need to be replaced.
Step 10: Finish The Toilet Installation
Attach the toilet seat and adjust the fill/flush settings in the tank to your preference. Run several test flushes. Finish by applying a neat bead of white silicone caulk around the base to create a clean, sanitary edge and help prevent rocking.
Bonus Step: Get Rid Of Your Old Toilet
Don’t toss a working old toilet in the trash. Consider donating it to a charity or selling it if it’s still in good condition—after a thorough cleaning. Many reuse centers and resale shops accept used fixtures.
Toilet Installation FAQs
Can I install a toilet myself?
Yes. Installing a toilet is a beginner-friendly plumbing project. Most toilets weigh 80–120 lbs, so choose a two-piece model if you’re working solo, and ask for help lifting heavier components when needed.
Do I need a plumber?
If any step feels beyond your skill or comfort, hire a professional. For routine replacements and installations, many homeowners complete the work themselves successfully.
Should I caulk around the toilet?
Yes. A silicone bead around the base improves appearance, helps prevent moisture and odors under the toilet, and can reduce rocking.
Other Toilet How-Tos
If you found this guide helpful, consider learning more about fixing a rocking toilet, converting to dual-flush, or unclogging drains—skills that complement toilet installation and maintenance.
*This post may reference products and tools for convenience; consider local availability and compatibility before purchasing.