Installing a toilet was one of the first DIY projects we tackled as new homeowners back in 2006. Nearly two decades and countless installs later, it’s a task I’m comfortable doing again and again. You’ll see photos from several bathrooms throughout this guide. A toilet install might seem intimidating or messy, but it’s a straightforward plumbing project most homeowners can complete with a few basic tools and a little patience.
These steps work whether you’re replacing an old toilet, reusing one that was removed during a remodel, or fixing a toilet that’s leaking or rocking. Follow the instructions carefully and you’ll have a secure, leak-free toilet in no time.
Tools & Supplies Needed
You don’t need many specialized tools to install a toilet. Below are the essential items to have on hand before you start.
- New toilet (if replacing)
- Measuring tape
- Wax ring kit (include an extra-thick ring if your flange is recessed)
- Adjustable wrench or groove-joint pliers
- Flathead screwdriver
- Rags and spare towels or blankets
- Sponge, paper towels, or small bowl for water removal
- Utility knife
- Hacksaw (for trimming bolts)
- White silicone caulk
- Level (optional)
- Gloves (optional)
If you’re reinstalling your current toilet, you won’t necessarily need a new one. This guide includes steps for reusing an existing toilet.
Steps To Install A Toilet
Read this full tutorial before you begin and gather your supplies. Here’s a quick overview of the main steps involved in a typical toilet installation.
- Measure the rough-in
- Purchase a new toilet (if needed)
- Remove the old toilet
- Prepare the floor and flange
- Install the wax ring
- Set the toilet bowl
- Bolt the bowl to the floor
- Install the tank
- Connect the water supply
- Finish the installation and caulk the base
Some steps may be skipped or modified if you are reusing the same toilet.
Step 1: Measure Your Rough-In
Before buying a new toilet, measure the rough-in distance: from the floor bolts to the finished wall behind the toilet. Most standard toilets require a 12″ rough-in, so confirm you have at least that much clearance using a tape measure. Older or compact bathrooms sometimes have a 10″ rough-in and need a compact toilet designed for that size.
Include the thickness of any baseboard in your measurement. Many toilet tanks sit well above the baseboard, so the important dimension is from the bolts to the finished wall surface.
Step 2: Purchase Your New Toilet
When choosing a toilet, consider rough-in size plus these common options and features:
- Round vs. Elongated Bowl: Elongated bowls are generally more comfortable; round bowls save space and are better for smaller bathrooms.
- Seat Height: Standard bowls sit about 14–15″ from floor to rim. Comfort- or chair-height toilets sit closer to 17″ and can be easier to use for many people.
- One- vs. Two-Piece: Two-piece toilets (separate bowl and tank) are lighter to handle during installation, while one-piece toilets offer a seamless look.
- Single- vs. Dual-Flush: Dual-flush models save water by offering separate flush options for liquids and solids. You can also add a dual-flush conversion kit to many toilets.
Other choices include color, styling, and unique designs like wall-mounted or square-bowl toilets. For a reliable, standard option, pick a well-reviewed model that matches your rough-in and desired bowl shape and height.
Step 3: Remove Your Old Toilet
If you have an existing toilet, remove it by reversing the installation steps. The basic sequence is:
- Turn off and drain the water
- Disconnect the water supply
- Remove the tank (if two-piece)
- Remove the bowl
- Plug the flange opening
Turn off & empty the water
Close the shutoff valve located behind the toilet by turning it clockwise until it stops. If it’s stiff, use a small amount of lubricant and avoid excessive force. Flush the toilet to empty the tank and bowl as much as possible, then remove leftover water with a sponge or small container.
Disconnect the water line
Unscrew the supply line from the bottom of the tank by turning the nut counterclockwise. Have a bowl or towels ready—some water may spill from the hose. You can leave the supply line attached to the wall fitting unless you plan to replace it.
Remove the tank
If you have a two-piece toilet, remove the tank first. Unscrew the nuts on the tank bolts located underneath the tank using a wrench. Use a screwdriver inside the tank to hold the bolts steady if they turn. Lift the tank straight up and set it on a towel or blanket to avoid cracking it on the floor.
Remove the bowl
Remove plastic bolt caps, then unthread the nuts from the two floor bolts holding the bowl. If caulk seals the base, score it with a utility knife. Rock the bowl gently side to side to break the wax seal, then lift it off and set it on a towel or blanket—position it upside down or on its side so the old wax doesn’t soil your floor covering.
Plug the flange opening
Immediately stuff a rag into the open flange to block sewer gases and prevent objects from falling in. Remember to remove this rag before installing the new toilet.
Step 4: Prepare the Floor & Flange
Clean all old wax, caulk, and debris from the flange and surrounding floor. Use a utility knife, putty knife, or scraper to remove as much wax as possible. Inspect the flange—the metal or PVC ring embedded in the floor—for cracks or damage; replace it only if it’s broken. Remove the old flange bolts and insert new bolts from your wax ring kit into the flange’s keyhole slots. Many kits include plastic clips that help keep the bolts upright.
If you are reinstalling the same toilet, clean old wax from the bottom of the bowl as well so the new seal seats properly.
Step 5: Add the Wax Ring
The wax ring seals the toilet to the flange and prevents leaks and sewer gas. Wax rings vary in thickness—use a standard ring or an extra-thick ring depending on how recessed the flange is relative to the finished floor. Many kits include two rings; having a backup is wise.
For easier alignment, press the wax ring onto the underside of the toilet bowl rather than onto the flange. Lay the bowl on a towel, position the ring around the outlet horn, and press it lightly so it stays in place during setting.
Step 6: Place the Toilet Bowl
This is the most delicate portion of the install. With the wax ring attached, lift the bowl and carefully lower it over the flange so the bolts pass through the bowl’s bolt holes. Remove the rag from the flange first. If the bowl is heavy, have a helper guide and support it. A useful trick is to slide short drinking straws over the bolts to make alignment easier—then remove the straws after seating the bowl.
Once the bowl is over the flange, press down firmly to compress the wax ring. Some people carefully sit on the bowl to apply even pressure and ensure a good seal. If the bowl is misaligned or a wax ring becomes deformed, remove the bowl and use a new wax ring—do not reuse a smashed ring.
Step 7: Bolt the Toilet Bowl
Place washers and nuts onto each floor bolt and hand-tighten them. Alternate tightening between bolts in small increments to keep the bowl level and avoid cracking the porcelain. Use a wrench only to snug them further—do not over-tighten. Trim any excess bolt length with a hacksaw, then snap on plastic bolt caps for a clean finish.
Step 8: Install the Toilet Tank
Set the tank onto the bowl, aligning the large rubber gasket with the outlet at the back of the bowl. Install the tank bolts with rubber washers and hand-tighten the nuts underneath. Alternate tightening the bolts gradually and evenly to prevent cracking and to keep the tank level. Use a screwdriver from above and a wrench below if needed.
Check that the tank sits flat on the bowl and adjust if necessary before fully tightening.
Step 9: Connect the Water Line
Reconnect the water supply hose to the tank by hand and tighten slightly with a wrench. Optionally use plumber’s tape on threaded fittings for extra security. Slowly open the shutoff valve and let the tank fill. Flush several times and inspect all connection points for leaks—at the supply hose, between the tank and bowl, and around the base. If you find a leak at the base, the wax ring may need to be replaced.
- Supply line to tank
- Tank-to-bowl gaskets and bolts
- Base seal around the wax ring
Step 10: Finish the Installation
Attach the toilet seat and adjust the flushing mechanism inside the tank as desired. Finish by applying a neat bead of white silicone caulk around the base of the toilet to improve appearance, reduce movement, and prevent spills or splashes from getting under the toilet rim. Avoid caulking the back of the toilet completely if local code or maintenance access considerations require a gap—some prefer to leave a small opening at the rear to detect leaks.
Bonus Step: Dispose of or Rehome the Old Toilet
After the new toilet is installed, clean up and decide what to do with the old one. If it’s still in good condition, consider donating it to a local charity or selling it. Clean it thoroughly before donating. If it’s damaged, check local waste disposal rules for large-item pickup or recycling options.
Toilet Installation FAQs
Can I install a toilet myself?
Yes. Installing a toilet is a beginner-friendly plumbing project if you can lift and handle the components safely. Most two-piece toilets break down into manageable pieces, and the process becomes easier with a helper.
Do I need a plumber?
If any step feels beyond your comfort level or if you encounter unexpected problems—broken flanges, unusual plumbing configurations, or persistent leaks—call a licensed plumber. For straightforward replacements and installations, many homeowners can complete the job themselves by following instructions carefully.
Should I caulk around the toilet?
Yes. A bead of silicone caulk around the base improves appearance, helps keep the toilet steady, and prevents moisture and debris from getting under the rim—this reduces odors and the risk of mold. Apply a smooth, continuous bead and wipe any excess for a clean finish.
Additional Toilet Resources
If you want to expand your bathroom DIY skills, consider guides on fixing a rocking toilet, converting a toilet to dual-flush, or unclogging drains without chemicals. Practicing basic maintenance and repairs will save time and money over the long run.
This article may reference product types and common accessories; always follow manufacturer instructions and local codes when installing plumbing fixtures.