Toilet replacement: DIY or hire a plumber?

Toilet replacement is the platonic DIY plumbing job. The mechanical work is simple — two bolts, a supply line, and gravity. The failure modes are visible (a drip you can see, not a hidden leak), the tools required are basic, and the typical DIY savings are $150–$300 on a 90-minute afternoon. Most plumbers who charge $500 to replace a toilet spend 45 of their 60 billable minutes drinking coffee.

Here's how to decide whether to DIY.

Start with three questions

1. Is the existing flange in good shape? Pop off the toilet tank lid, turn off the shutoff valve, and flush once. Look under the toilet base — the flange is the plastic or metal ring bolted to the floor. If it looks intact and sits level with (or slightly above) the finished floor, you're good. If the flange is cracked, rotted, or sits well below the tile, this job needs a pro.

2. Is the floor around the toilet solid? Push gently on the floor around the base of the toilet. Solid = fine. Spongy or flexing = the subfloor has rotted from a prior hidden leak, which is a call-a-pro situation. You'll need to pull the toilet, assess the damage, and potentially do subfloor and tile work.

3. What's the rough-in? Measure from the finished wall (not the baseboard) to the center of the closet bolts. Most homes are 12 inches. Older homes are sometimes 10 or 14. Get this measurement before you shop — buying a 12-inch rough-in toilet for a 10-inch rough-in bathroom is the #1 DIY mistake on this job.

If all three answers are "yes" / normal, this is a clear DIY.

What you'll spend

Scenario	Parts	Labor	Total
DIY, budget toilet	$120	—	$140–$180
DIY, mid-range toilet	$280	—	$300–$380
Hired, you supply toilet	$120	$220	$340–$400
Hired, plumber supplies toilet	$180	$220	$400–$500
Hired, bidet-seat or smart toilet	$350–$1,200	$280	$630–$1,480

The savings math is cleanest on the basic replacement: DIY for $150 vs hired for $400. A mid-range toilet with soft-close seat: DIY $300 vs hired $500. The delta holds regardless of how fancy the toilet is — you're saving roughly $180–$240 of labor.

The actual job

Budget 90 minutes if you've never done it, 45 minutes if you have.

1. Shut off the supply valve under the toilet. Flush to drain the tank. Use a sponge and bucket to remove the remaining water from the bowl and tank — you don't want it sloshing when you tip the unit.
2. Disconnect the supply line from the tank. Bucket underneath for drips.
3. Unbolt the tank from the bowl (if your toilet is a two-piece). Set the tank aside on a towel.
4. Unbolt the bowl from the floor — the closet bolts under decorative caps at the base.
5. Lift straight up. The old wax ring will resist. Set the toilet on a trash bag.
6. Scrape the old wax ring off the flange. A putty knife works. Stuff a rag into the drain opening while you work so sewer gas doesn't fill the room.
7. Check the flange for damage. If it's fine, set a new wax ring on it (wax side up for a standard ring; follow instructions for a wax-free ring).
8. Lower the new toilet straight down onto the bolts. Don't rock it side-to-side trying to seat it — that compromises the seal. Sit on it gently to press it down.
9. Tighten the closet bolts evenly — snug, not Hulk-tight. Porcelain cracks. Alternate left/right a few turns each until firm.
10. Reattach the tank (if two-piece). Don't over-tighten the tank bolts either.
11. Connect a new braided-stainless supply line. Always use new — reused supply lines are the source of most post-install leaks.
12. Turn water on slowly. Check for leaks at the shutoff, the supply line, the tank, and the base. Let the tank fill, flush once, check again.

The most common DIY mistake on this job isn't installation technique — it's buying the wrong rough-in. Measure before you leave for the store.

When to hire instead

Hire a plumber when:

• The existing flange is broken, rotted, or below floor level.
• The floor around the toilet is spongy (subfloor damage).
• You have a bidet-seat, smart toilet, or electric toilet that needs an outlet run.
• You're moving the drain location (never DIY).
• You have a concrete slab floor with a compromised flange.
• You've had two back-to-back floods from prior DIY plumbing attempts and your confidence is spent.

Fair plumber price: $300–$500 for a straightforward like-for-like replacement (you supply or they supply a standard toilet). Anything over $700 without clear justification — flange replacement, subfloor repair, rough-in conversion — warrants a second quote. See our signs of an overpriced quote guide.

One pro tip

Before you drop the new toilet onto the wax ring, set it in place loosely — without the wax ring — and do a test-fit. You want to confirm the closet bolts stick up through the holes in the base, that the tank lid has clearance to the wall behind, and that the overall position looks right. Once a wax ring compresses, it's single-use — you don't want to lift the toilet back up to rearrange anything.