A tub to shower conversion costs anywhere from about $1,000 for a prefabricated stall to $15,000 for a custom tiled walk-in, according to Angi’s 2026 data and a current HomeGuide estimate. That spread is too wide to plan around, so the first decision is whether your house should lose a tub at all.
Both estimates are national, and no independent county-level price data turned up for Marin, Sonoma or Napa. This guide uses the published ranges with their source and year, and it never presents a Projects Within Reach price, because the studio has not published one. If you are weighing a bigger bathroom project, our bathroom remodel ideas post covers the wider picture.
The decision comes before the price
Decide whether the house should keep a tub
Convert when your house has a second tub somewhere, when the tub is a storage shelf for bottles, or when a step-over wall is becoming a problem for someone who lives there. Hold off when the bathroom you are changing holds the only tub in the house.
A tub earns its place in a family home with small children, and it carries resale appeal. We come back to that below. A shower earns its place when people use it daily, which describes most primary bathrooms. Take the Tuesday-morning test: count how many baths anyone in the house took last year, and let that number guide the final call.
Tight rooms change the answer too. In a small bathroom, dropping a 60-inch tub can free room for a vanity with real counter space, and our guide to maximizing space in a small bathroom shows how that trade plays out. In a primary bath, the shower often becomes the centerpiece upgrade, and our look at primary bathroom upgrades that boost comfort and home value weighs it against other choices.
Tub to shower conversion cost by type of job
Compare published estimates by project type
Published estimates split into three jobs. A prefab stall swaps the tub for a prefabricated shower base and surround. A tiled walk-in gets a custom pan, waterproof membrane and tile. The third job moves the drain or valve, so plumber hours drive the price, and Angi lists plumbers at $45 to $200 per hour.
| Job | Published estimate | Source and year |
|---|---|---|
| Prefab shower stall in the tub’s footprint | $1,000 to $8,000 installed | HomeGuide, read October 2026 |
| Tiled walk-in shower | $3,500 to $15,000 | Angi 2026 and HomeGuide, read October 2026 |
| Wet-area conversion, materials and labor | $8,000 to $15,000 | Home Depot, read October 2026 |
HomeGuide puts its national average at $7,000 with a typical range of $2,000 to $12,000. Angi’s range runs from $1,200 to $15,000, with totals near $3,000 for common stall types. The Home Depot cost guide says wet-area renovations like this one run about $8,000 to $15,000.
Why do the numbers differ by so much? Each source prices a different job. A prefab insert that reuses the existing drain and valve costs a fraction of a tiled shower with a new pan and a relocated drain. Ask any contractor which job the quote describes, and ask what it leaves out.
Angi also lists permits at $200 to $2,000, while HomeGuide puts them at $30 to $400. Even permit fees disagree, which tells you how local the number is. Our guide to planning a guest bathroom renovation budget walks through the line items, and our tips to help you save when remodeling show where trimming is safe.
The money goes under the tile
Much of a tiled shower’s cost sits where nobody looks once the job is done. Three areas decide whether it lasts: demolition, plumbing and waterproofing.
Demolition and what hides behind the old tub
HomeGuide lists removing the tub and debris at $70 to $800, and repairing walls and the damaged subfloor at $170 to $1,800 once the old fixture is out. That range reflects how little anyone knows before demolition. A tub that leaked for years can leave soft framing or stained subfloor, and nobody sees it until the tub is gone.
I tell clients to hold a line in the budget for repairs behind the tub, because old plumbing and rot show up often once the tub comes out.
Plumbing, the drain and the valve
The shower valve controls temperature and flow, and swapping it runs $225 to $575 on HomeGuide’s list. Reusing the tub’s drain location keeps plumbing at $500 to $1,100 in HomeGuide’s table. Since plumbers bill by the hour, every fixture you move adds time.
A shower drain often sits in a different spot from the tub drain. Moving it means opening the shower floor, so ask whether your quote moves the drain.
Waterproofing, slope and the flood test
A tiled shower floor has to slope toward the drain. The consultants at CTaSC describe a pre-sloped mortar bed at one-quarter inch per foot, covered by a liquid or sheet waterproof membrane, then a second mortar bed at least 1.5 inches thick. Their guidance puts the final slope at no less than one-quarter inch and no more than one-half inch per foot.
They also recommend a flood test for at least 24 hours, run after the membrane has cured for a day. This test costs a little time and no materials. Ask your contractor whether it is in the schedule, because tile hides every leak path that a skipped test would have caught. Tile choice comes later, and our guides to bathroom tile and flooring options and bathroom tile pattern ideas cover it.
Size rules for the new shower
Check the finished dimensions before ordering
A common tub footprint is 60 by 30 inches, a size Angi’s table lists. A shower in that space can fall short of the code minimum if you add a bench or a thick wall panel. The 2025 California Plumbing Code section 408.7, as republished by GoCodebook, requires a finished interior of at least 1,024 square inches that can hold a 30-inch circle. That area must stay clear up to 70 inches above the drain, except for valves, shower heads, shelves and grab bars.
The NKBA bathroom planning guidelines recommend more room than the code floor. They also cite a lower model-code minimum of 30 by 30 inches, which is why you should confirm which adopted edition your city enforces.
| Item | Number | Source |
|---|---|---|
| Finished interior area | 1,024 square inches, 30-inch circle | California Plumbing Code 408.7 |
| Recommended interior size | 36 by 36 inches | NKBA guidelines |
| Clear entry width | 22 inches minimum | NKBA, citing the IRC |
| Clear space outside the entry | 24 inches | NKBA guidelines |
| Controls above the floor | 38 to 48 inches | NKBA guidelines |
A standard 60-by-30-inch tub footprint is 1,800 square inches, so a straight swap leaves plenty of margin. The squeeze comes when you add a built-in bench, a curb and thick tile, so draw the finished dimensions before you order a shower base. Our guide to maximizing space in a guest bathroom and our designer rules for a timeless bathroom cover clearance choices.
Permits and your building department
Confirm local requirements before ordering
Permit rules vary by city and county, and they change, so treat any online summary, this one included, as a starting point only. Marin County’s building permit page, updated September 1, 2026, offers an online maintenance permit for bath plumbing fixtures that replace something that exists now. It offers an online minor improvement permit for a non-structural bathroom remodel of 400 square feet or less. Bigger jobs need plans up front, and the county says that route takes six to eight weeks.
This guide found no usable Sonoma or Napa page, so call your local building department before you order anything. Never assume your job is exempt. Moving a drain or valve changes the plumbing, so ask the department what your specific job needs and who pulls the permit.
The our process page lays out the steps of a project from first sketch to final walkthrough.
The only-tub resale trap
Keep a tub when it is the only one
Removing a tub can cost you buyers. In 2022 the National Association of Realtors reported on an NAHB survey of home buyers from 2021. It found that 42 percent of first-time buyers call a shower and tub in the primary bath desirable, and 30 percent call it essential. Those are national numbers from a 2021 survey, so a Marin buyer may answer another way. A local agent can tell you how nearby listings treat the question.
So keep one tub. If the house has two bathrooms, convert the one that gets less use and leave a tub in the hall bath, where a bath for kids or a soak for a sore back stays available. I tell clients that a house with a single bathtub should not lose it unless aging in place outweighs resale.
Our guide to luxury shower and bathtub ideas shows what a tub can look like in a small bath, if you decide to keep it.
Failure points to catch early
Resolve four common risks before work begins
Most trouble with a conversion falls into four groups. The first is hidden rot found at demolition, which turns a quoted price into a change order. The second is a shower that ends up too small after the bench and tile thickness are counted, which can fail the code minimum outright. The third is a missed blocking step: NKBA recommends reinforcing walls at construction so grab bars can support 250 pounds, and adding that reinforcement later means opening a finished wall.
The fourth is a glass door priced late. Angi lists framed doors at $200 to $800 and frameless doors at $600 to $2,500, a gap that can erase savings elsewhere, so settle the glass choice early. Fixtures matter too, and our guide to primary bathroom materials compares finishes that hold up to daily use.
Keeping the number honest
Ask for an itemized scope and allowances
Ask each contractor for an itemized bid that names the shower type, the membrane system, the drain location and the glass. Budget conversations happen at the beginning, not halfway through, so ask for written allowance lines for repairs behind walls and a clear rule for how unused allowance returns to you.
A designer who draws the shower with dimensions lets every contractor price the same job, and someone on your side reads the bids against the drawing. Our piece on working with a kitchen and bath designer describes that role. At Projects Within Reach, the design work and the advocacy during construction are Jenn’s, and the contractor is a separate hire.
FAQ
Walk-in shower conversion cost
Angi and HomeGuide both put a custom tiled walk-in at $3,500 to $15,000 in the estimates we read, with Angi listing a wider $800 to $15,000 range for walk-in conversions as a whole. The top of the range pays for tile, a custom pan, glass and plumbing changes. A stall insert costs less.
Tub liners and refinishing as cheaper options
HomeGuide lists tub refinishing at $350 to $600 and a tub liner at $1,700 to $2,500. Both keep the tub, so they sidestep the resale question. They do not give you a shower, so they suit people who want a fresher tub rather than an easier step.
Grab bars and seats for aging in place
NKBA recommends a shower seat 17 to 19 inches above the floor and 15 inches deep, with walls reinforced for grab bars rated to 250 pounds. It also suggests thresholds of no more than one-half inch. HomeGuide lists grab bars at $25 to $370, so planning ahead costs little.
Your next step is a conversation
Bring your layout, household needs and budget
If you are still unsure whether your bathroom should keep its tub, book a free discovery call. It is an honest conversation about your home, with no sales pitch and no obligation. Ask for our free “Planning your remodel budget” guide while you are there, and use the contact page to start. We will talk through your bathroom layout, your household habits and your budget range before anyone sketches a thing. You can read more about our studio first.