Replacing Toilet: A Step-by-Step DIY Guide With Real Costs

Roughly 70% of homeowners can swap out a toilet in a single morning with $40 in supplies and a 12-inch crescent wrench, yet plumbers routinely charge $250 to $600 for the same job. Replacing toilet work is one of the highest-value DIY projects in the house — straightforward physical labor, no electrical risk, and a finished result that lasts 25 years. The catch is in three or four small details that separate a clean install from a slow leak that rots the subfloor. Here is the real process, top to bottom.

Part of our Bathroom Remodeling & Flooring guide — explore the full guide →

When to Replace Instead of Repair

Most toilet problems — running fill valve, weak flush, slow leak from the tank-to-bowl gasket — are $20 part swaps that take an hour. Full replacement makes sense when:

• The bowl or tank has a visible crack (always replace, never patch)
• You are remodeling and changing the height (10-inch standard to 16.5-inch comfort height)
• The toilet uses 3.5+ gallons per flush (pre-1992 models — replacement saves 12,000+ gallons per year)
• The flange is broken or sitting more than 1/4 inch above finished floor
• Persistent ring stains or porcelain damage that no longer cleans up

A quality toilet runs $150 to $400. Premium models with coated trapways and dual-flush mechanisms run $400 to $700. Budget Glacier Bay units from Home Depot start at $99 and work fine for rentals or basements.

Choosing the Right Toilet

Three measurements matter before you buy. The rough-in distance — center of the closet bolts to the finished wall behind — must match. Standard is 12 inches; some older homes are 10 or 14. Bowl shape (round front for tight bathrooms, elongated for comfort), and bowl height (standard 14-15 inch seat height versus 16.5 inch ADA comfort height).

Top picks by category:

• Best overall: Toto Drake CST744SL ($380), exceptional flush, 12-inch rough-in, 1.6 GPF
• Best budget: Kohler Cimarron K-3589 ($200), reliable, comfort height
• Best one-piece: American Standard Cadet 3 ($330), seamless skirted design, easy to clean
• Best dual-flush: Toto Aquia IV ($600), 0.8/1.28 GPF, premium materials

Tools and Supplies You Need

Total parts cost runs $30 to $50 if your shutoff valve is in good shape. Pick up:

• New wax ring with horn ($5) or a Fluidmaster Better Than Wax ring ($8) — the rubber-style is more forgiving
• Closet bolts kit with brass nuts and washers ($4)
• New flexible braided supply line, 12-inch length ($6 to $10)
• Plumber’s putty or 100% silicone caulk ($5)
• Adjustable wrench, channel locks, putty knife, towels, bucket, level
• Optional: hacksaw or oscillating tool for stubborn old bolts

If your shutoff valve is a 30-year-old multi-turn that does not fully close, also grab a quarter-turn brass replacement valve ($12) and SharkBite or compression fittings.

Step-by-Step Removal

Plan on 30 to 45 minutes for removal of the old toilet:

1. Turn off the supply valve behind the toilet, then flush and hold the handle to drain the tank
2. Sponge or vacuum out remaining water in tank and bowl (a wet/dry vac speeds this up dramatically)
3. Disconnect the supply line from the bottom of the tank
4. Remove the two nuts from the closet bolts at the floor — if rusted, cut with a hacksaw or oscillating multi-tool
5. Rock the toilet gently side to side to break the wax seal, then lift straight up and walk it outside
6. Stuff a rag in the open drain to block sewer gas and prevent dropped tools
7. Scrape off all old wax from the flange with a putty knife

Inspecting the Flange

This is the step most DIYers skip — and the one that causes most callbacks. Check the closet flange (the round fitting at floor level that the toilet bolts to):

• Cracked or broken: replace with a new PVC flange ($8) or use a Sioux Chief stainless reinforcing ring ($15)
• Sitting below finished floor by more than 1/4 inch: install a flange extender (Oatey Set-Rite, $10 to $20)
• Sitting above finished floor: do not stack wax rings — re-set the flange flush with the finished floor
• Loose: re-screw to subfloor with stainless steel screws

Installing the New Toilet

With prep done, the install moves fast:

1. Set new closet bolts in the flange slots, head down, with plastic keepers to hold them upright
2. Press the wax ring (or rubber ring) onto the bottom horn of the toilet
3. Carefully lower the toilet straight down, aligning bolts through the holes — do not rock or twist as you set it, this distorts the seal
4. Press down with body weight to compress the wax fully — you should feel the toilet settle to the floor
5. Add washers and brass nuts, hand-tight then 1/4 turn with a wrench, alternating sides — do not overtighten or you will crack the porcelain
6. Cut bolts to length with a hacksaw and snap on the bolt caps
7. Install tank on bowl per manufacturer’s instructions if a two-piece
8. Connect the supply line, hand-tight plus 1/4 turn
9. Turn on water, let tank fill, flush 3 to 5 times to check for leaks at the base, supply line, and tank-to-bowl gasket

Caulking the Base

Plumbing code in most jurisdictions requires caulking the toilet base to the floor. Run a clean bead of 100% silicone caulk (GE Silicone II, $7) around the front and sides — leave a 2-inch gap at the back so any leak from the wax ring becomes visible quickly instead of rotting your subfloor undetected. Smooth with a damp finger or caulk tool.

Common Mistakes That Cause Leaks

Watch for these and you will avoid the do-over:

• Reusing the old wax ring — always replace, they cost $5
• Overtightening the closet bolts and cracking the bowl base
• Skipping flange repair when the flange is below the finished floor
• Using two wax rings stacked — this almost always leaks
• Forgetting to remove the rag from the drain (yes, this happens)
• Over-tightening the supply line and stripping the threads

When to Call a Plumber

Hire it out if: the flange is broken in concrete subfloor, the closet bend (the elbow under the flange) is damaged, you find rotted subfloor underneath, or the rough-in plumbing needs to be moved. A flange replacement on a slab can be a 4-hour job with concrete cutting — that is plumber territory. Otherwise, replacing toilet work is one of the most satisfying afternoon projects in homeownership.

Total time: 90 minutes to 3 hours depending on how stubborn the old bolts are. Total cost: under $400 for a quality toilet plus $40 in supplies. Versus a $500 plumber bill, that is real money for a few hours of work.