Project Guide

How to Install a Toilet

Difficulty: IntermediateTime: 2-4 hours Print

Replacing and installing a new toilet isn’t as hard as it may sound. All you need are a few hours, a helper, and the right tools and toilet parts for the job. Before you begin learning how to install a toilet, choose your new toilet, and if you aren’t replacing an existing toilet, make sure you have plumbing ready for the new installation.

Watch the video below to learn how to put in a toilet, or follow the below guide on how to remove and install a toilet.

1. Remove the Old Toilet

If you’re replacing a toilet, you’ll first need to remove the old toilet. The old toilet’s flange and bolts can be reused when installing a new toilet if they’re in good condition.


Here’s an overview on how to remove an existing toilet for replacement:


  • Turn off the water at the shut-off valve located either on the wall or floor near the toilet.
  • Flush the toilet to drain all the water from the tank and toilet bowl. Use a plunger to force any remaining water down the drain line. While wearing rubber gloves, remove any remaining water from the tank with a sponge and a bucket.
  • Disconnect the supply line with an adjustable wrench. If the line has never been removed or has been connected for an extended period, it might be a little hard to loosen at one or both connection points. If that’s the case, use a heavy-duty lubricant to break down any corrosion.
  • Have a bucket and rag on hand to catch and wipe up any standing water that leaks from the supply line.
  • If you’re working alone, it’s usually easier to first separate the tank from the bowl. Lifting both pieces together can be difficult for one person.
  • Use an adjustable wrench to remove the bolts that connect the bottom of the tank to the bowl.
  • Lift the tank straight up from the bowl and set it aside.
  • Pop open the toilet bolt caps. Use a screwdriver if necessary.
  • Use a pair of pliers or an adjustable wrench to remove the nuts and washers on the bolts that secure the bowl to the floor. If you find the nuts are rusted in place, use the heavy-duty lubricant to loosen the nuts. Then turn the screws to create as much space as you can at the base of the bolts. Use a hacksaw to cut the bolts off.
  • If your toilet has been caulked around the base, use a utility knife to score through the caulk seam.
  • Gently rock the toilet bowl back and forth until you work it free and can lift it. Move it to the side to expose the old toilet seal.
  • Remove the old toilet seal using a putty knife. Wipe away any excess with a damp rag or sponge.
  • Stuff a rag into the open line in the floor to prevent sewer gases from venting into your home. Remove the rag before installing the new toilet.

2. Inspect the Toilet Flange

Before answering “How do you install a toilet?”, it’s important to determine whether you need to replace the toilet flange. The flange creates a connection between the floor and toilet and provides a connection point for the hardware found on the base of the toilet. If it is cracked or broken, replace it with a matching flange.

Tip: If you’re unsure of what type of replacement flange to buy, simply snap a photo of your old flange and use image search in The Home Depot Mobile App to find similar products.

3. Install New Toilet Seal

You have two options for placing the new toilet seal or wax ring:

  • You can rest the new toilet bowl on its side on a padded surface to protect the floor and the toilet and attach the replacement seal to the bottom of the bowl. The benefit to this technique is that you can be sure that the ring is in the proper position when placing the toilet over the flange.
  • The more popular option is to place the seal in position on the flange prior to lowering the bowl into place.

Tip: If thick tile has been added to your bathroom since the original toilet was installed, you may need a thicker toilet seal or wax ring.

4. Place Toilet on Flange

Now that you’ve removed the old toilet and prepped the location, you’re ready to learn how to put in a toilet.

  • Place the toilet bowl onto the flange, aligning the bolt holes in the base of the bowl with the bolts in the flange.
  • If it helps, you can hold the bowl by the inside rim instead of the outer edges to get a better grip and more control as you lower it.
  • Press down to set the seal.

Tip: Be very careful not to move or tilt the toilet after setting the wax seal on the flange since you could break the seal and cause future leaks.

5. Bolt Toilet to Floor

  • Place a washer and nut on each toilet bowl bolt and evenly tighten the nuts onto the bolts.
  • Alternate from one side of the toilet to the other as you tighten the nuts a little at a time. Be careful not to over-tighten the nuts and crack the porcelain bowl.
  • If the bolts extend too far over the top of the washers and nuts, cut off the excess with a hacksaw.

Tip: Don’t caulk a new toilet around the base. In the event of a leak, the caulk will trap the water under the toilet and cause serious damage to your floor.

6. Attach the Tank

If you have a two-piece toilet, you’ll need to attach the tank to the bowl. If you have a one-piece toilet, you can skip this step, since the bowl and tank are permanently attached.

  • If not already attached, install the “tank to bowl” gasket onto the base of the flush valve. Insert the tank bolts and washers from inside the tank.
  • Place the tank onto the bowl, aligning the shank of the bolts with the holes in the bowl. If the bolts extend too far over the washers and nuts, cut off the excess with a hacksaw.
  • Secure the tank to the bowl by alternately tightening each tank bolt until the tank pulls down and meets the bowl.
  • Re-attach the supply line to the exposed portion of the fill valve sticking out of the bottom of the tank and to the supply valve coming out of the wall or floor.

7. Install Toilet Seat and Lid and Test for Leaks

The last step for how to install a toilet is choosing the toilet seat.


  • Since there are many types of seats and lids, make sure to select a toilet seat that will fit your toilet model. Elongated toilet seats are the most common seat type, since they’re more comfortable. Round toilet seats may be more common in small homes and apartments where space is a concern.
  • Find the correct toilet seat size by measuring your new toilet, if necessary.
  • A specialty item such as a raised or heated toilet seat may have special installation requirements.
  • Position and attach the new seat according to the manufacturer’s installation instructions.
  • Test the toilet for leaks. Slowly turn on the water shut-off valve and allow the tank to fill. Flush the toilet and focus on the base of the toilet and the point at which the tank and bowl meet. Add leak-detecting dye to make seeing leaks easier.

Now that you know how to change a toilet, installing a new toilet is a task that you and a helper can complete in a single day. If you’d rather have a professional install a toilet for you, rely on our toilet installation services. For installing a toilet in a new location, hire our plumbing services to prep the space beforehand.