What You'll Need Before You Start

Replacing a toilet requires a few specific tools and parts, most of which you can find at any hardware store for under $100 total. The actual job takes two to four hours if you've never done it before, and the hardest part is usually disconnecting the old toilet and getting it out of the bathroom — it's heavy and awkward, not complicated.

Before you buy anything, measure the distance from the wall behind the toilet to the center of the bolts that hold it down. This measurement, called the rough-in distance, is almost always 12 inches in North American homes, but older houses sometimes have 10-inch or 14-inch rough-ins. If you buy a toilet with the wrong rough-in, it won't fit properly and you'll have to return it.

You'll also need to decide whether you want a standard two-piece toilet (tank and bowl separate) or a one-piece model (tank and bowl fused together). One-piece toilets are easier to clean and look sleeker, but they cost more and are heavier to install. Two-piece toilets are the standard choice for DIY replacement because they're lighter and cheaper.

Key Takeaways

  • You need a new toilet, a wax ring, bolts, a fill valve, a flapper, and basic tools like a wrench, screwdriver, and plunger before you start.
  • Measure the rough-in distance (wall to bolt center) before buying — it's usually 12 inches but can be 10 or 14 inches in older homes.
  • Shutting off the water supply at the valve behind the toilet is the first step, and you should test it before you disconnect anything.
  • The wax ring creates a watertight seal between the toilet and the drain pipe, and it must be replaced every time you remove the toilet.
  • If water leaks from under the toilet after installation or the toilet rocks when you sit on it, call a plumber — these mean the wax ring didn't seal properly.

Tools You'll Need to Have on Hand

Start with an adjustable wrench or a socket wrench set — you'll use this to disconnect the water supply line and remove the bolts that hold the toilet to the floor. A screwdriver (both flathead and Phillips) helps with the fill valve and other small connections. A plunger is essential in case you need to clear the drain before installation, and a bucket or large towel catches water that spills when you disconnect the supply line.

You'll also want a utility knife to scrape away the old wax ring after you remove the toilet, and a flashlight or headlamp so you can see what you're doing under and behind the toilet. A level (even a small one) helps you make sure the new toilet sits flat — a rocking toilet is uncomfortable and can damage the wax ring seal over time.

If you don't own these tools already, you can rent a toilet flange wrench from most hardware stores for a few dollars. This tool makes removing the bolts much easier, though an adjustable wrench works fine if you're patient.

The Parts You Need to Buy

The new toilet itself is the biggest purchase. A basic two-piece toilet costs $150 to $300 at most hardware stores. The toilet should come with a fill valve (the mechanism that refills the tank) and a flapper (the rubber seal that lets water flow from tank to bowl), but check the box to be sure. If either is missing, you'll need to buy them separately for $15 to $40 each.

The wax ring is the most critical part you'll buy separately. This is a ring of wax that sits between the toilet base and the drain opening in the floor — it creates a watertight seal. A standard wax ring costs $3 to $8 and comes in a cardboard tube. Buy one even if the toilet comes with one, because you may need a backup if the first one tears or doesn't seat properly. Some people prefer a wax-free ring made of rubber or foam, which costs a bit more but can be reused if you remove the toilet again.

You'll also need new bolts and washers to hold the toilet down. These usually cost $5 to $10 for a set and come in different lengths depending on your floor type (ceramic tile, vinyl, or wood). The hardware store staff can help you pick the right length if you bring a photo of your floor or a sample of the old bolts.

Shutting Off the Water and Draining the Tank

Look behind the toilet for a small valve where the water supply line connects to the tank. This is the shutoff valve, and turning it clockwise stops water from flowing into the tank. Turn it as far as it will go — you should feel resistance but don't force it, as these valves can break if you're too rough.

After you shut off the water, flush the toilet to empty the tank. If the tank doesn't empty completely, use a sponge or towel to soak up the remaining water and wring it into a bucket. This step prevents water from spilling all over your floor when you disconnect the supply line.

If the shutoff valve doesn't work — meaning water still flows into the tank after you turn it — you'll need to shut off the main water supply to your house instead. This valve is usually in the basement, crawl space, or under the kitchen sink. If you can't find it or it doesn't work, call a plumber before you proceed.

Removing the Old Toilet and Preparing the Floor

Disconnect the water supply line by turning the nut that connects it to the tank with your wrench. Have a bucket or towel ready — there's usually a little water left in the line. Next, remove the bolts that hold the toilet to the floor. These are usually covered by plastic caps that pop off with a flathead screwdriver. Use your wrench to turn the nuts counterclockwise until they come free.

Once the bolts are loose, rock the toilet gently side to side to break the seal between the wax ring and the floor. Then lift the toilet straight up and set it aside on a tarp or old towels — it will be heavy (40 to 80 pounds depending on the model) and may have a little water in the bowl. If you're alone, ask someone to help you lift it.

Now scrape away the old wax ring with a utility knife. This is messy but necessary — you can't install a new toilet on top of old wax. Scrape until the floor is smooth and clean, then wipe it with a damp cloth. If the flange (the metal or plastic ring that sits in the floor opening) is cracked or broken, you'll need to replace it before installing the new toilet. This is a job for a plumber, as it involves cutting into the drain pipe.

Installing the New Toilet

Press the new wax ring firmly onto the bottom of the toilet bowl, centering it over the opening. Some people prefer to place the wax ring on the flange instead — either way works, but putting it on the bowl is easier because you can see what you're doing. Make sure the ring is seated all the way around with no gaps.

Lower the toilet straight down over the bolts, aligning the bolt holes in the base with the bolts sticking up from the flange. Don't twist or rock it side to side as you lower it — you want to compress the wax ring evenly. Once the toilet is resting on the floor, hand-tighten the bolts, then use your wrench to tighten them in a crisscross pattern (like tightening a car wheel). Tighten a little on one side, then a little on the other, until the toilet is snug. Don't over-tighten — you can crack the porcelain.

Use your level to check that the toilet is sitting flat. If it rocks when you sit on it, loosen the bolts slightly and slide shims (thin plastic wedges) under the base until it's level, then re-tighten. Trim the bolts flush with the top of the nuts using a hacksaw or bolt cutter, then snap the plastic caps back on.

Reconnecting the Water Supply and Testing

Reconnect the water supply line by hand-tightening the nut, then use your wrench to snug it up another quarter turn. Don't over-tighten — you can crack the fitting. Turn the shutoff valve counterclockwise to restore water to the tank. The tank should fill within a minute or two. If water is spraying or dripping from the connection, turn the valve back off and tighten the nut a bit more.

Once the tank is full, flush the toilet a few times and watch for leaks. Check under the toilet and around the base — if you see water pooling, the wax ring didn't seal properly. This usually means the toilet is rocking slightly or the wax ring wasn't pressed on evenly. You'll need to turn off the water, disconnect the supply line, remove the bolts, lift the toilet, and try again with a new wax ring.

Let the toilet run for a few minutes to make sure the fill valve and flapper are working smoothly. The tank should fill and stop automatically, and the bowl should drain completely when you flush.

When to Call a Plumber Instead

If the shutoff valve behind the toilet doesn't work and you can't find or operate the main water shutoff, stop and call a plumber. Proceeding without shutting off the water will flood your bathroom.

If the flange is cracked, broken, or sits below the floor level, you need a plumber. Replacing a flange requires cutting into the drain pipe and is beyond a typical DIY job. If the drain pipe itself is damaged or leaking, that's also a plumber's job.

If you've installed the toilet and water is leaking from under the base after multiple attempts with new wax rings, the flange may be damaged or the floor may be uneven in a way that prevents a good seal. A plumber can diagnose the problem and fix it properly.

Frequently Asked Questions

Can I reuse the old wax ring?

No. Wax rings are designed to be used once and then discarded. Once you remove a toilet, the wax ring loses its shape and won't seal properly if you try to use it again. Always buy a new one.

What if I can't get the old bolts off?

If the bolts are rusted or stuck, spray them with penetrating oil (like WD-40) and wait 15 to 30 minutes, then try again. If they still won't budge, you can cut them with a hacksaw or bolt cutter. This is slow but works. If you're struggling, it's reasonable to call a plumber at this point.

Do I need a plumber's license to replace a toilet?

No. Toilet replacement is a permitted DIY job in most places. However, some cities require a permit if you're replacing the flange or doing work on the drain line itself. Check with your local building department if you're unsure.

How long does a new toilet last?

A standard toilet lasts 20 to 30 years with normal use. The fill valve and flapper may need replacement after 10 to 15 years, but the bowl and tank can last much longer if they're not cracked or damaged.

What's the difference between a round and elongated toilet seat?

Round seats are smaller and take up less space — they're common in bathrooms with tight layouts. Elongated seats are longer front to back and are generally more comfortable. The toilet bowl shape determines which seat fits, so measure your bowl before buying a seat. Most new toilets come with a seat, but if you need to replace it later, they cost $20 to $100.