How Much Does It Cost to Turn a Half Bath Into a Full Bath?

How Much Does It Cost to Convert a Half Bath to a Full Bath?

Most homeowners pay $5,000 to $25,000 to convert a half bath into a full bath. A shower that fits in the existing room sits at the low end. A tub, new framing, and moved plumbing sit at the high end, and a wall move can push the bill past $25,000.

Project Type	Typical Total	What Pushes It Up
Stall shower in the existing footprint (three-quarter bath)	$6,000–$12,000	Custom shower work, finishes, ventilation, and added electrical
Shower with rerouted plumbing or drain	$10,000–$18,000	Longer drain runs, opened floors or walls, venting changes, and added labor
Tub-shower combo or a wall move (full bath)	$15,000–$25,000+	Tub installation, framing, structural work, plumbing relocation, and a larger finished footprint

Other guides show different numbers because they price different jobs. HomeAdvisor lands on the same $5,000 to $25,000 range. Angi’s range is wider, at $1,800 to $25,000, and This Old House puts the average cost of adding a shower to a half bath at about $8,000. Ask every contractor what the quote includes: demolition, plumbing, waterproofing, tile, fixtures, and permits.

To estimate your own layout, try our bathroom remodel cost calculator. This page covers converting an existing half bath. If you only want a shower, see our guide to adding a shower to a half bath. Building a brand-new bathroom costs more and is covered in the next steps below.

Is Converting a Half Bath to a Full Bath Worth It?

It’s usually worth it when the conversion gives your home its first or second full bath. Angi estimates the project adds about 5.7% to a home’s value and recovers around 60% of its cost at resale. Adding only a shower adds about 5% to 6%. The payoff is highest in homes that don’t already have two full baths. If you have two, a third adds little.

At a 60% return, a $12,000 conversion adds about $7,200 in value (our estimate). You also get a second place to shower, which matters every morning whether or not you ever sell.

How return changes with spending

The Journal of Light Construction’s 2025 Cost vs. Value report tracks full bathroom projects, not half-to-full conversions. It still shows a clear pattern: mid-range work recovers the most, and a new bathroom addition costs far more than a remodel.

Project (2025 National Average)	Job Cost	Resale Value	Cost Recouped
Mid-range bath remodel	$26,138	$20,915	80%
Upscale bath remodel	$81,612	$34,000	42%
Mid-range bathroom addition	$60,645	$32,347	53%

Converting space you already own avoids the cost of an addition, which is why a half-to-full conversion is one of the cheaper ways to add a bathroom. Keep your finishes in the mid-range and you stay near the top of the return curve.

When it pays off most

Your Situation	What to Expect
You have only one full bath	Strongest case; this is where Angi sees the highest return
You already have two full baths	Little added resale value; the case rests on daily convenience
Your only shower is upstairs	A ground-floor shower helps with aging in place and adds about 5% to 6% in value
Your home has no tub anywhere	Choose a tub-shower combo; Angi’s rule of thumb is one tub per home
The existing bathrooms are dated or leaking	Fix those while you convert; worn fixtures put buyers off

A higher appraised value can also raise your property taxes. Talk to a local agent about what buyers near you expect, and compare other projects in our cost vs. value guide. If you can’t decide between a tub and a shower, our bathtub vs. shower comparison can help.

Half Bath vs. Three-Quarter Bath vs. Full Bath

The finished room’s name sets how much space and money the project needs. Many homeowners and some listings call a three-quarter bath “full,” so confirm what you’re pricing.

Bathroom Type	Fixtures
Half bath	Toilet and sink
Three-quarter bath	Toilet, sink, and a stall shower
Full bath	Toilet, sink, and a tub (often with a shower)

A tub typically adds $3,000 to $8,000 over a stall shower in the same room, and it needs about twice the floor space. If your home already has a tub elsewhere, we think a three-quarter bath is the better choice for a converted powder room. If this would be your only tub, the extra cost is easier to justify, because a home with no tub can be a harder sell to families with young children.

Half Bath to Full Bath Cost Breakdown

These costs sit inside the project totals above, so don’t add them together. Labor, the vanity, the toilet, wall tile, and electrical work make up the rest of the price.

Cost Item	Typical Cost
Prefab shower	$600–$2,500
Custom-built shower	Up to $5,200
Alcove tub (unit only)	$400–$2,500
Plumbing adjustments	$600–$1,500
Waterproofing	$800–$2,000
Flooring (about 40 square feet)	$400–$3,000+
Moving a non-load-bearing wall	$2,000–$5,000
Moving a load-bearing wall	$5,000–$10,000+
Permits	$250–$1,500

Shower or tub

The fixture is your biggest single choice. A prefab shower is the cheapest route, and a custom-built one can reach $5,200. Fixture-only ranges run wider in other guides: HomeAdvisor lists $400 to $8,500 for a shower and $2,000 to $9,400 for a tub, depending on type and finish. If you want both, a tub-shower combo fits them in one footprint. Our types of showers guide can help you compare layouts.

Plumbing

Plumbing is often the largest line in the budget. The $600 to $1,500 in the table covers adjustments to existing lines. Bringing new supply and drain lines to a shower that never existed costs more: This Old House assigns about $5,500 of its $8,044 average shower addition to plumbing installation. The farther the shower sits from your current pipes, the closer you get to that figure.

Waterproofing

A shower or tub puts far more water in the room than a toilet and sink do. Crews apply waterproof membranes to the walls and floor and seal every joint so water stays out of the framing and subfloor. Budget $800 to $2,000 for most conversions.

Flooring

Powder room flooring often can’t handle a shower. For a 40-square-foot room, sheet vinyl or standard ceramic tile runs about $400 to $800 installed. Porcelain tile or luxury vinyl plank runs $800 to $1,600, and natural stone or custom tile costs $1,600 to $3,000 or more. Browse waterproof flooring for wet areas.

How Much Space Do You Need?

Fixture or Room	Space Needed
Stall shower	About 15 square feet
Bathtub	About 30 square feet
Full bathroom (toilet, sink, and tub or shower)	About 40 square feet
Minimum shower size under the International Building Code	30 by 30 inches

Most powder rooms can fit a stall shower without moving a wall. A tub usually means borrowing space from a closet, hallway, or next-door room. Beyond the 30 by 30 inch minimum, most codes also call for 22 inches of clearance in front of the shower entry and at least 70 inches of ceiling height over the shower area. Confirm the rules with your local building department.

If space is tight, a corner shower, a wall-hung toilet, and a pedestal sink save floor area. Check standard shower sizes against your room before you commit, and see standard bathroom sizes for typical layouts.

Factors That Affect the Cost

• Shower or tub: A tub typically adds $3,000 to $8,000 over a stall shower.
• Plumbing location: The farther the shower sits from existing drain and supply lines, the more new piping you need.
• Floor type: If new drain lines must run through a concrete slab, the crew has to cut and patch the floor, which adds labor.
• Wall moves: Moving a wall adds $2,000 to $10,000 or more, depending on whether it carries load.
• Ventilation and electrical: A shower needs a window or an exhaust fan that vents outside, and it often calls for new lighting and ground-fault outlets.
• Hot water: Make sure your water heater can keep up with a new shower.
• Materials: Tile, glass, and fixtures can swing the price by thousands.
• Surprises: Water damage or mold behind old walls adds time and cost once demolition starts.

If your project includes taking out walls or fixtures, read our guide to bathroom demolition. Plumbers typically charge by the hour, so see plumber cost per hour for current rates.

Permits and Timeline

Most areas charge $250 to $1,500 for the permits on a bathroom conversion, which cover plumbing, electrical, and general building work. Large metro areas often sit at the top of that range. Your contractor usually pulls the permits and builds the fees into the quote. Skipping plumbing permits can cause problems at resale and complicate an insurance claim.

Most conversions take two to four weeks, counting planning, permits, and construction. A shower-only job typically takes one to three weeks, according to This Old House. Rerouted plumbing, extra electrical work, or structural repairs add time. See our bathroom remodel timeline for more detail. Most conversions follow these steps:

1. Plan and budget: Set your budget, layout, and fixtures.
2. Get permits: Your contractor usually handles this.
3. Demolish: Remove the old fixtures, the floor, and any walls that need to change.
4. Rough in: Run the new plumbing and electrical lines.
5. Waterproof and install: Seal the shower area, then set the shower or tub, tile, toilet, and sink.
6. Finish: Add paint, lighting, and accessories.

DIY vs. Hiring a Pro

Hire licensed pros for the plumbing, electrical work, and waterproofing. Mistakes in those areas cause leaks and failed inspections, and Angi warns that a sloppy remodel can lower your home’s value. If you want to save money, take on painting, basic demolition, or other finish work yourself. Ask each contractor for an itemized quote that lists labor, materials, and possible extra costs, and set aside a contingency fund for surprises.

How to Save Money

• Choose a stall shower: It avoids the $3,000 to $8,000 a tub typically adds.
• Buy prefab: A prefab shower costs $600 to $2,500, while a custom-built one can reach $5,200.
• Keep fixtures in place: Moving a wall adds $2,000 to $10,000 or more.
• Choose mid-range finishes: Mid-range remodels recovered 80% of their cost in the 2025 Cost vs. Value report, compared with 42% for upscale ones.
• Compare quotes: Get at least three, and see how to evaluate remodel quotes.

Half Bath to Full Bath FAQs

What Are Your Next Steps?

Decide whether you want a three-quarter bath or a full bath, measure your room, and compare a few quotes. Check our guide to adding a bathroom if you’re thinking bigger, and see our small bathroom ideas for tight layouts.

Modernize can connect you with trusted local bathroom professionals to compare prices, designs, and timelines for your conversion. Browse our list of the best bathroom remodeling companies to get started.

Sources

• Block Renovation, half bathroom to full conversion costs, permits, and designs
• HomeAdvisor, how much it costs to add a bathroom
• HomeAdvisor, small bathroom remodel cost (2025)
• Angi, is it worth converting a half bath to a full bath
• This Old House, adding a shower to a half bath (2025)
• Journal of Light Construction, 2025 Cost vs. Value report