How to Install a Toilet—It’s Not as Intimidating as You Think

Jun 22, 2023

By Jennifer Beck Goldblatt

It may not be the best seat in the house, but it's certainly an essential one. Which is why learning how to install a toilet is a skill that could come in handy one day for many homeowners. (Removing a toilet is even easier.) After all, like virtually every other thing in your house, toilets have a lifespan. Of course, you can always call in a professional plumber or handyman to do the job, but this DIY plumbing job is actually pretty simple and a bathroom repair you can do on your own. Tackling the task of toilet installation yourself, or with a DIY–savvy friend, could save you a few hundred dollars. Not to mention that since you’ll have a new toilet, it will actually look stain-free when you clean it.

Frank Decker, plumbing program coordinator at Porter and Chester Institute in Hamden, Connecticut, agrees. "Most homeowners can replace their toilet if they have the proper materials, tools, and background knowledge," he admits. "They also need to be able to lift it too."

Here's everything you need to know about how to install a toilet, and how to get the job done in eight steps.

Household toilets get used a lot, especially when you have more than a few people at home. That wear and tear can take a toll on the toilet's lifespan. A good toilet can last for decades with proper maintenance, Decker says. And although you may end up with a running toilet at one point, internal components like the floater and flapper can be replaced to fix the problem, so you won't need to install a new toilet just because of that. The toilet bowl and tank can last at least a decade. However, once you notice cracks or you see water seeping onto the floor, installing a new toilet is likely in your future.

Broken components aren't the only reason to replace a toilet, though. Toilet technology has come a long way, especially in recent years, Decker says. The 1.28 GPF toilet models available now are more efficient, use less water, and offer a wide variety of added features like UV lights for sanitizing and paperless cleaning (if you’re into that sort of thing).

It's best to shop for a new toilet in person, so you can take it for a spin, so to speak. Toilets come in different heights (often 14 or 16 inches) and styles (elongated or round), and are a matter of personal preference for many. You should also consider your space. Typically, you should allow for 12 inches from the center of the bowl to the nearest wall. Larger or smaller toilets may require different space allotments.

Take a walk around any home improvement store or fixture showroom, and you’ll notice that new toilets start at around $100 and can go up into the thousands. And even though you may not need or want one with all of the bells and whistles mentioned above, Decker says there are some advantages to spending a bit more. "The quality of the components inside the toilet are often better in correlation with the price," he says. "These are usually a step up from the base model. A name brand is also often better quality."

Yes, unless you have issues with lifting heavy weight—a toilet typically weights around 100 pounds. If you’re in your own home, feel like doing a home improvement project, and can get your hands on the necessary tools, then go for it. Those renting should definitely check with the landlord before embarking on a DIY project like this.

Some people may be able to do this DIY project on their own, Decker says. But it's important to keep in mind that the average toilet weighs anywhere from 60 to 120 pounds, depending if it is a two- or one-piece toilet. Having someone nearby to lend a helping hand, at least when physically moving the toilet, is preferable.

The majority of new toilets come boxed with most of the supplies you’ll need to install them. Otherwise, you’ll need an adjustable wrench, which you likely used when you removed your old toilet. Here's what you should have on hand:

Take a look at the area where the bowl will be sitting. If the subfloor appears wet, moldy, or shows any signs of damage, you’ll want to replace or repair it before installing a new toilet. Keep in mind that the toilet flange (also called a closet flange) needs to rest on top of the finished floor. The flange connects the toilet bowl to the drainage system and also secures the entire unit to the floor with a wax seal (also called a wax gasket or wax ring). Never stack two wax seals on top of each other to make up for a difference in height, Decker warns. Over time, they will lead to plumbing issues, including leaks, and you’ll need to reinstall the toilet.

New toilets should come with an instruction and installation manual specific to them, but the basic steps are fairly universal. Here's what you need to do, step by step.

If you did not remove the old toilet, now is the time to do it. Bring the new toilet you’ll be installing into the bathroom and place it near your workspace. New toilets usually come with a set of toilet bolts (also called closet bolts or Johnny bolts). Use a wrench to secure the bolts on either side of the flange, which is the toilet waste pipe in the floor.

Use your hands to place the new wax ring between the toilet bolts, making sure it is centered on top of the flange. If the wax ring has a sloped edge, place it in a way that the narrow side touches the flange.

Center the wax ring between the bolts on the flange.

As you lower the toilet bowl, make sure that both toilet bolts pass through the holes in the toilet bowl. These are located on either side of the bowl, near the bottom. Gently rock the toilet back and forth on top of the wax ring until the base is flush with the floor. If a toilet is installed on an uneven floor, or if the toilet flange is too high off the bathroom floor, the toilet will need to be shimmed to make up for the excess space. To do this, use wooden shims, metal washers, or coins to fill in the area until the toilet is level. Once the toilet bowl is attached to the wax ring, do not move it. Doing so will compromise the seal and can lead to leaks in the future.

Place the included plastic washer over the toilet bolts so they lay flat, then place the included metal washer over each toilet bolt so it lays flat on top of the plastic washer. Thread the nuts clockwise on each side of the toilet bolts and secure with a wrench until snug. If desired, you can use a hacksaw to trim the excess length of the bolts down, leaving about half an inch above the nut. Top with the decorative bolt caps that came with the toilet.

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Place plastic washers over the bolt to secure it.

If you purchased a two-piece toilet, you’ll need to install the tank. If not, skip to the next step. Lift the tank into place, making sure each of the tank bolts goes into the corresponding hole on the toilet bowl. Screw the bolts in by hand and then use a wrench to tighten them.

The toilet tank and the toilet bowl should fit together like a puzzle.

The water line is what connects the toilet tank to the water supply, and it is typically located on the wall behind the tank or nearby in the floor. Screw one end of the water supply line onto the bottom of the toilet tank, then attach the opposite end onto the supply valve near the wall or floor. Tighten both ends with a wrench.

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Turn on the water supply—the shutoff valve is located near the back of the toilet where you connected the water line—and flush the toilet several times. If you notice any leaks, try tightening the bolts to fix the issue.

Use a wrench to tighten the water line and prevent leaks.

Position the toilet seat assembly (that's the part you sit on) over the bowl. Insert the plastic bolts through the seat back and the bowl's seat holes, then tighten the nuts by hand. When purchasing a toilet seat, pay attention to the shape of the toilet bowl, which could be round or elongated.

Tighten the plastic bolts with a screwdriver for a secure fit.

To finish, apply a waterproof silicone caulk where the base of the toilet bowl meets the floor, and let dry for at least three to six hours before using the toilet. If you have extra caulk, you can use your finger or a wallpaper smoother for a seamless application.

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Use your finger to smooth out any excess caulk at the base of the toilet bowl.

It's better if you don't. Most new toilets come with a new wax ring, and if they don't, you can get one for just a few dollars at any hardware or home improvement store. It's an important piece of what keeps your toilet working well, so having a fresh and new one makes sense.

Technically, a new toilet will work as soon as it's hooked up to the water supply line. But waiting until the caulk is fully dry is wise. Refer to the directions on your caulk tube for an ideal dry time, but know that most should be set within three to six hours.