Why is my toilet leaking at the base?

Wondering where the water comes from?

Where a toilet can leak, in plain English

A toilet leaking at the base usually has water getting out at one of four spots: the water line, the tank, the seal under the toilet, or a drain backing up. Water runs downhill, like rain down a window, so a drip from up high often ends up on the floor at the base.

Each number matches a step below. Water runs downhill, so a drip from 1 or 2 can end up on the floor at the base too.

The valve and the supply line. Water comes out of the wall through a small valve, then up a short hose to the bottom of the tank. A loose nut or a worn hose drips all the time, even when nobody flushes.
The tank seal and tank bolts. The tank sits on the back of the bowl on a thick rubber seal, held by two or three bolts. When the rubber gets old, water drips out under the tank.
The wax ring and floor bolts. A ring of wax seals the bottom of the toilet to the drain pipe. Two floor bolts hold the toilet down. If the toilet rocks, the seal breaks, and water seeps out when you flush.
The drain under the floor. Every drain in the house runs into one main pipe. If it clogs, water from the shower or washer can push out under the toilet.

Sometimes nothing is leaking at all. On humid days, a tank full of cold water sweats like a glass of iced tea, and the drops run down to the floor.

A toilet that runs all the time keeps the tank cold, so it sweats more. Our guide to a toilet that keeps running covers that. If the toilet also clogs or other drains are slow, see a toilet that won't flush or a clogged shower drain.

Smell sewage in the house? See our guide to a house that smells like sewer.

Who to call

Rather not do it yourself? Call a plumber.

That's a fine choice. Maybe you're busy. Maybe you're selling the house and just want it done right. A plumber can reset the toilet with a new seal or put in a new toilet.

$50–$200Reset with a new wax ring

$350–$800New toilet, put in

Most plumbers charge $45–$200 an hour, and some add a fee to come out. A broken flange or a soft floor costs more.

Find plumbers near you

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What to say

Calling a pro? Here's what to say.

A few lines to read when they pick up, and the questions to ask before anyone comes out.

Before you call

Rent? Call your landlord first.

Home warranty? Call them first.

4.5 stars or more, and a license number.

Say this

Hi. My toilet is leaking at the base. When's the soonest you can get here? And what's your fee for the visit? Does it go toward the repair?

Always ask

What's your fee to come out, and does it go toward the repair?
Do you charge by the job or by the hour?
Will you tell me the full price before you start any work?

Watch out if

They push a full replacement on the first visit for a small problem.
They won't give you a price before starting.
They add an emergency fee without telling you first.

Feeling pushed to decide on the spot? You can say no and hang up. You owe nothing for a phone call.

Know what's wrong before they come

Answer up to 5 quick questions. We'll give you the words a pro uses.

Answer the questions →

More of a list person?

Common toilet leaks, causes, tests and costs

Find the row that sounds like your toilet. The quick test is something you can check yourself in a few minutes.

What you notice	What it probably is	Quick test	Do it yourself	With a pro	Verdict
Hose or its nut is wet; drips even with no flush	The water hose to the tank is loose or worn	Wrap a paper towel around the hose	Free	$50–$200	FIXSee the answer: The water hose to the tank is loose or worn
Valve behind the toilet drips at its handle or nut	The water valve behind the toilet is leaking	Wrap a paper towel around the valve	Pro job	$60–$150	CALLSee the answer: The water valve behind the toilet is leaking
Whole tank beaded with water on humid days	The tank is sweating, not leaking	Food coloring in the tank: no color outside	Free	Not needed	FIXSee the answer: The tank is sweating, not leaking
Drips under the tank, at the bolts or the gap	The seal between the tank and the bowl is leaking	Food coloring in the tank, then look underneath	Free	$50–$600	FIXSee the answer: The seal between the tank and the bowl is leaking
Toilet rocks; water at the base after flushing	The floor bolts are loose	Grip the bowl and try to rock it	Free	Not needed	FIXSee the answer: The floor bolts are loose
Water at the base after flushing; may rock or smell	The seal under the toilet is worn	Food coloring in the bowl, then flush	Pro job	$50–$200	CALLSee the answer: The seal under the toilet is worn
A crack line where water seeps out	The tank or the bowl is cracked	Food coloring, then look for a colored line	Pro job	$100–$800	CALLSee the answer: The tank or the bowl is cracked
Water at the toilet when the shower or washer drains; bowl gurgles	A drain clog is pushing water out under the toilet	Run the shower and watch the bowl	Pro job	$100–$800	CALLSee the answer: A drain clog is pushing water out under the toilet
Water by the toilet only when the shower runs; bowl stays calm	Water from the shower or tub, not the toilet	Run the shower and watch the floor	Pro job	$45–$200	CALLSee the answer: Water from the shower or tub, not the toilet
Water once in a while; the tests show nothing	A spill or splash, not a leak	Paper towels at the base for a few days	Free	Not needed	FIXSee the answer: A spill or splash, not a leak

2026 U.S. averages, rounded. Pro prices include parts and labor. Most plumbers charge $45–$200 an hour, and some add a fee to come out. Nights, weekends and big cities cost more. See all repair prices

Want proof it's a leak?

The food-coloring test

Two food-coloring tests tell a leak from sweat, and the tank from the seal underneath. This Old House uses the same tests.

Tank first. Wipe the tank and floor dry. Put about 10 drops of food coloring in the tank, not the bowl. Don't flush. Wait 30 minutes, then look under the tank and on the floor.
Then the bowl. Put a few drops in the bowl and flush. Watch the floor at the front and sides of the base.

Colored drips under the tank: the tank seal or a tank bolt is leaking.
Clear beads all over the tank, no color: the tank is sweating, not leaking.
Colored water at the base after a flush: the wax ring under the toilet has failed. Call a plumber.
Color comes out along a line in the porcelain: the toilet is cracked.

Not sure it's safe to keep flushing?

Stop flushing right away if…

Water keeps spreading across the floor. Turn the valve behind the toilet to the right (clockwise).
Water comes through the ceiling below, or a new stain shows up there.
The water is dirty or smells like sewage. Wear gloves to clean it up.
Water comes up at the toilet when the shower runs or the washer drains. Stop running water.
The tank is cracked and leaking. Turn the valve off and flush to empty the tank.
The floor around the toilet feels soft or spongy.

Valve won't turn, or it sprays? Shut off the main water valve for the house, and call a plumber.

Got a big plumber's quote?

Repair the toilet, or replace it?

Most toilets leaking at the base need a repair, not a new toilet. HomeAdvisor lists $50–$200 to replace a wax ring, and Fixr lists $60–$200. A new toilet, installed, runs $350–$800 (HomeGuide). Ask yourself three things:

Is the tank or bowl cracked? Then it's a new tank ($100–$400, Fixr) or a new toilet.
Is it the wax ring? That's a repair. A broken flange or a soft floor adds to the price, so ask for a written price first.
Is the toilet old, and does it also clog or run a lot? A new toilet may be worth it while the plumber has it off the floor.

Example: $150 to reset a toilet with a new wax ring is in the normal range. Being told you need a new toilet for a leaking seal is worth a second opinion.

Ran into a word you don't know?

Toilet words, explained

Tap through these before you start. The drawings show roughly what each part looks like.

Tank: The box on the back of the toilet that holds the water for a flush. The lid is heavy, so set it on a towel.
Water valve (shutoff valve): The small valve behind the toilet, near the floor. Turn it to the right (clockwise) to stop the water to the tank.
Supply line: The short hose from the water valve up to the bottom of the tank.
Fill valve: The tall part inside the tank that lets water in after a flush. The supply line screws onto its bottom.
Tank bolts and seal (tank-to-bowl gasket): Two or three bolts and a thick rubber seal that hold the tank on the back of the bowl.
Floor bolts (closet bolts): The two bolts at the base that hold the toilet to the floor. Small plastic caps cover them.
Shims: Thin plastic wedges that fill gaps under the base, so the toilet can't rock on an uneven floor.
Wax ring: The seal between the bottom of the toilet and the drain in the floor.
Flange (closet flange): The ring on top of the drain pipe in the floor. The floor bolts hook into it, and the wax ring sits on it.
Porcelain: The hard, shiny material toilets are made of. It's strong, but it can crack from a bump or bolts that are too tight.
Sweating (condensation): Drops of water that form on a cold tank when the air is humid, like on a glass of iced tea.
Tank liner: A foam lining that sticks inside the tank. It keeps the outside of the tank from getting cold enough to sweat.
Paper-towel test: Paper towels wrapped around each part. The one that gets wet first shows where the leak starts.
Food-coloring test: A few drops of food coloring in the tank or the bowl. Colored water outside the toilet means a leak, not sweat.
Main drain (sewer line): The one big pipe that carries water from every drain out of the house.
Shower pan: The waterproof floor under a shower's tile. If it cracks, water can leak under the bathroom floor.

Still have questions?

Questions people ask most

Is a toilet leaking at the base an emergency?

A toilet leaking at the base usually isn't an emergency, but don't let it go for weeks. Act now if water keeps spreading, comes through the ceiling below, or it's dirty water. Stop flushing and turn the valve behind the toilet to the right (Roto-Rooter, Mr. Rooter).

Why is my toilet leaking at the base when I flush?

A leak that shows up only when you flush usually means the wax ring under the toilet has failed. Loose floor bolts can let the toilet shift and break that seal (Mr. Rooter, This Old House).

Why is my toilet leaking at the base without flushing?

Water that shows up without anyone flushing usually comes from the supply line, the valve or the tank-to-bowl seal. On humid days it may just be the tank sweating. The food-coloring test tells you which (This Old House).

Is my toilet sweating or leaking?

A food-coloring test tells you: colored water outside the tank means a leak, and clear beads all over the tank mean sweat. Put about 10 drops in the tank, don't flush, and check after 30 minutes (This Old House).

Why is my toilet leaking at the base when the shower is on?

Water at the toilet's base when the shower runs or the washer drains often means a drain clog is pushing water out under the toilet. If the bowl rises, bubbles or gurgles, stop running water and call a plumber today. If the bowl stays calm, the water may be coming from the shower or tub instead (This Old House, Angi).

How do I know if my toilet's wax ring is leaking?

The usual signs are water around the base after you flush, a toilet that rocks, and a sewer or urine smell near the floor. Water stains on the ceiling below or a soft, spongy floor near the toilet mean the leak has gone on a while, so call soon. To check, put food coloring in the bowl, flush, and watch the base for colored water (Oatey, Mr. Rooter, This Old House).

How long does a toilet wax ring last?

A wax ring that was put in right can last many years, often as long as the toilet itself. It can fail sooner if the toilet moves or the flange under it is damaged, so snug loose floor bolts early (Oatey).

Should you caulk around a toilet?

Caulk around the base is a choice, but it won't fix a leak under the toilet. The seal underneath still has to be replaced. Experts disagree on caulking itself: This Old House says most plumbers skip it because it can hide a leak, and some local codes require it. Oatey recommends caulking the whole base to keep mop water out.

Can I replace a toilet wax ring myself?

Many handy people replace a wax ring themselves. Home Depot and Oatey call it an intermediate job: under 2 hours, with a helper to lift the toilet. We send most people to a plumber. The toilet is heavy, the drain is open, and a soft floor or broken flange needs fixing at the same time.

Why is my toilet still leaking after a new wax ring?

A toilet that still leaks after a new wax ring is often moving on loose floor bolts, or sitting on a cracked or broken flange (Oatey). Check the hose and the tank bolts too, because those leaks also end up at the base. If a plumber or store put in the ring or a new toilet, call them first.

How much does it cost to fix a toilet leaking at the base?

Most people pay about $50–$200 for a plumber to reset a toilet with a new wax ring (HomeAdvisor $50–$200, Fixr $60–$200). A new toilet, installed, is about $350–$800 (HomeGuide; Fixr $400–$800). Tightening a bolt or a hose costs nothing.

Who do I call for a toilet leaking at the base?

Call a plumber for a worn wax ring, a cracked toilet, a leaking valve or water coming up from a drain. Try the free checks first: the paper-towel test, the food-coloring test and the hand-tight hose nut. Renters should call their landlord first, and people with a home warranty should check it first.

How we built this

The questions follow the order a plumber checks a toilet leaking at the base: when the water shows up, which paper towel gets wet first, the valve and hose, the food-coloring tests, whether the toilet rocks, and whether a drain is backing up. Each answer makes some causes more likely and others less likely.

Prices are 2026 national averages from published repair-cost guides, rounded. Your local prices will differ.

How we make money: some links go to parts stores that pay us a small commission, and some pro listings pay us when you call them. Verdicts come from the diagnosis, not from who pays more.