The short answer
Bathrooms are the most expensive rooms in a house per square foot. A small room holds plumbing supply and drain lines, electrical circuits, ventilation, waterproofing, and several kinds of tile, and four or five different trades have to work in it one after another. A 40 square foot bathroom can cost more to remodel than a 300 square foot living room.
Three decisions set most of the price: what you do with the tub or shower, whether any fixture moves, and how much tile you install. Floor area matters less than the fixture count, because a toilet, a vanity, and a shower cost about the same in a small bathroom as in a large one. The calculator above prices each decision separately.
How the calculator works
- Fixtures are flat costs. The tub or shower, vanity, toilet, plumbing changes, electrical package, demolition, and permit are each priced as a single installed amount with a low, typical, and high value.
- Surfaces scale with floor area. Flooring, heated floor mats, and paint are multiplied by the floor area. Wall tile is estimated at 1.2 square feet of wainscot per square foot of floor, so a 40 square foot bathroom gets about 48 square feet.
- Local cost level. Every line except the permit is multiplied by 0.9 in lower-cost areas and 1.2 in high-cost metros.
- Overhead and contingency. A general contractor adds 10% to 20% for overhead and profit. Your contingency percentage is then applied to the whole amount.
The formula is: total = (sum of selected items × local factor) × (1 + contractor markup) × (1 + contingency).
Cost assumptions
These are the installed-cost figures behind the calculator, at the national baseline. They are planning ranges compiled from published 2026 remodeling cost guides and supplier pricing, not quotes.
| Item | Unit | Low | Typical | High |
|---|---|---|---|---|
| New tub with prefab surround | Flat | $1,500 | $3,000 | $5,000 |
| New tub with tiled surround | Flat | $4,000 | $7,000 | $11,000 |
| Tiled walk-in shower with glass | Flat | $6,000 | $10,000 | $16,000 |
| Stock single vanity and top | Flat | $800 | $1,500 | $2,800 |
| Semi-custom or double vanity | Flat | $2,000 | $3,500 | $6,000 |
| Custom double vanity | Flat | $4,000 | $6,500 | $11,000 |
| New toilet | Flat | $400 | $700 | $1,300 |
| Flooring: waterproof vinyl plank | Sq ft | $6 | $9 | $14 |
| Flooring: porcelain or ceramic tile | Sq ft | $14 | $22 | $32 |
| Flooring: natural stone | Sq ft | $22 | $35 | $55 |
| Tile wainscot | Sq ft of wall | $14 | $22 | $32 |
| Heated floor | Sq ft | $12 | $18 | $28 |
| Move one or more fixtures | Flat | $1,500 | $3,500 | $7,000 |
| Exhaust fan, lighting, GFCI outlets | Flat | $800 | $1,800 | $3,500 |
| Drywall repair and paint | Sq ft of floor | $8 | $13 | $20 |
| Demolition and disposal | Flat | $800 | $1,500 | $2,800 |
| Permits and inspections | Flat | $200 | $500 | $1,200 |
Five bathrooms, priced
These examples use the national baseline and a 10% contingency.
| Project | What changes | Low | Typical | High |
|---|---|---|---|---|
| Half bath refresh, 20 sq ft | Stock vanity, toilet, vinyl plank floor, fan and lighting, paint. No contractor markup, demolition, or permit. | $2,500 | $4,900 | $9,100 |
| Budget full bath, 40 sq ft | Tub with prefab surround, stock vanity, toilet, vinyl plank floor, fan and lighting, paint. You hire the trades directly. | $5,300 | $10,300 | $18,400 |
| Mid-range full bath, 40 sq ft | Tub with tiled surround, stock vanity, toilet, porcelain tile floor, fan and lighting, paint, permit. General contractor. | $9,500 | $18,200 | $32,600 |
| Primary bath, 100 sq ft | Tiled walk-in shower with glass, double vanity, toilet, porcelain tile floor, fan and lighting, paint, permit. General contractor. | $15,000 | $27,200 | $47,500 |
| Upscale primary bath, 100 sq ft | Walk-in shower, custom double vanity, stone floor with heat, tile wainscot, and relocated fixtures. General contractor. | $23,700 | $42,700 | $75,200 |
The mid-range full bath works out to about $455 per square foot and the primary bath to about $272. Per-square-foot pricing is a poor way to budget a bathroom for exactly this reason.
The tub and shower decision
The wet area is the largest single line in most bathroom remodels, and the options differ widely.
- Tub with a prefabricated surround. An acrylic or fiberglass tub with matching wall panels. It installs in a day or two, has few seams to leak, and is the least expensive route.
- Tub with a tiled surround. A new tub with tile on three walls over a waterproofed backer. More labor, more design choices, and a finish most buyers prefer.
- Tiled walk-in shower. A sloped, waterproofed shower pan, tiled walls, a niche, and a glass enclosure. Frameless glass alone often costs $1,500 to $3,500. A curbless entry costs more because the floor framing has to be lowered or the surrounding floor raised.
Waterproofing is the part of the job you cannot see and the part that matters most. Ask each bidder which waterproofing system they use behind and under the tile, and whether they flood-test the pan before tiling. A leak discovered a year later means tearing out the new work.
Why moving fixtures costs so much
Every fixture is tied to a drain that slopes to the main stack and a vent that rises through the roof. Supply lines are easy to reroute. Drains are not. Moving a toilet even a few feet means opening the floor, and if the floor is a concrete slab, cutting and patching concrete. On an upper floor, the joists limit where a drain can run at all.
Keeping the toilet, the tub or shower drain, and the vanity where they are is the most effective way to control cost. If the layout truly does not work, moving the vanity is usually the cheapest change and moving the toilet the most expensive.
Costs people forget
- What is behind the tile. Rotted subfloor around the toilet or tub, corroded galvanized or cast iron pipe, and mold are common finds in older bathrooms. Use a 15% to 20% contingency for a home more than 40 years old.
- Ventilation. A new exhaust fan should be ducted to the outside, not into the attic. If the old one was not, the duct run is extra.
- Electrical code updates. Bathroom outlets need ground-fault protection, and a remodel often triggers a dedicated circuit that an older bathroom lacks.
- Accessories. Mirrors, towel bars, a medicine cabinet, a shower niche, and blocking in the walls for future grab bars. Blocking costs almost nothing while the walls are open.
- Lead paint and asbestos. In homes built before 1978, contractors must follow the EPA's lead-safe work rules, and old sheet flooring may need testing before removal.
- Living without the bathroom. If it is the only one in the house, plan the schedule and a fallback before demolition day.
How much should you spend?
A common rule of thumb puts a bathroom remodel at 3% to 7% of the home's value, toward the upper end for a primary bathroom. Enter your home value in the calculator to see where your budget falls.
Resale data supports staying in the middle. In Zonda's 2025 Cost vs. Value Report, a midrange bath remodel costing $26,138 added $20,915 to resale value, about 80% of its cost. A universal design remodel costing $42,183 recovered about 61%, and an upscale remodel costing $81,612 recovered about 42%. The renovation ROI calculator compares these with 25 other project types, and our guide to matching your reason for remodeling to the return helps decide how far to go.
Ways to lower the cost
- Leave every fixture where it is.
- Refinish a sound cast iron or steel tub rather than replacing it. Reglazing costs a few hundred dollars.
- Tile only where water lands. Tile the shower walls and the floor, and paint the rest with a moisture-resistant finish.
- Choose a standard-size vanity. Stock sizes of 24, 30, 36, 48, and 60 inches cost far less than a custom width.
- Use large-format porcelain. It looks like stone, needs less grout, and installs faster than small mosaic tile.
- Pick a semi-frameless or framed glass door over frameless, or a fixed glass panel over a hinged door.
- Get three itemized bids that name the waterproofing method, the tile allowance per square foot, and who buys the fixtures.
Timeline and permits
A full bathroom remodel usually takes three to five weeks of construction. The sequence is fixed: demolition, rough plumbing and electrical, inspection, backer board and waterproofing, tile, grout, paint, then fixtures and glass. Mortar, waterproofing, and grout each need curing time, and custom shower glass is measured only after the tile is finished, then takes one to two weeks to arrive.
Permits are generally required for new or moved plumbing, new circuits, a new fan duct, and wall changes. Replacing a toilet, vanity, or faucet in place usually is not. Your renovation plan should allow for the rough-in inspection before the walls are closed. For choosing who does the work, see DIY versus hiring professionals.
Keep the paperwork
A bathroom remodel is a capital improvement, so its cost is added to the basis of your home and can reduce the taxable gain when you sell. The capital gains on home sale calculator shows what documented improvements are worth. Keep the contract, paid invoices, the closed permit, fixture model numbers and warranties, and photos of the plumbing and waterproofing taken before the walls were closed. Those photos are the only record of where the pipes run.
What the estimate leaves out
The calculator does not price adding a bathroom where none exists, enlarging the room, structural repairs, replacing the main drain stack, a new water heater, steam showers, freestanding tubs, window changes, mold remediation, asbestos or lead abatement, design fees, or sales tax. Treat the result as a range to test contractor bids against.
Cost assumptions last reviewed November 2026.