Tub to Shower Conversion Kit: Complete Guide for Homeowners

The alcove bathtub that came with your house was probably chosen by a builder, not by anyone who has to step over a 15-inch wall every morning. A tub to shower conversion kit replaces that tub with a low-threshold shower base and matching wall panels, usually in the same 60-inch by 30- or 32-inch footprint. Kits range from about $600 to $3,500, and installed projects typically total $3,000 to $8,000. The catch is that a kit only works well when it fits the alcove exactly and the drain is relocated correctly. Get those two things right and the rest is straightforward.

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

What a Tub to Shower Conversion Kit Includes

Every tub to shower conversion kit centers on a shower base (sometimes called a pan) sized to drop into the space the tub leaves behind. Most kits also include three wall panels: a back wall and two end walls. Beyond that, contents vary by price tier.

• Base-only kits ($250 – $700): A single acrylic or composite pan. You supply walls, drain, and door separately.
• Base and wall kits ($600 – $1,800): Pan plus three- or five-piece wall surround, often with molded shelves and a seat.
• Complete kits ($1,500 – $3,500): Base, walls, drain assembly, glass door or fixed screen, and sometimes a valve trim package.

Check whether the drain is included. Many budget kits ship without one, and a proper 2-inch shower drain with a compression or glue-in body costs another $30 to $90.

Materials Compared: Acrylic, Fiberglass, and Solid Surface

Material choice affects durability, feel underfoot, and how the kit ages over ten or fifteen years.

For most homeowners, a reinforced acrylic base with a mortar or foam bed underneath is the sweet spot. Gelcoat fiberglass works for rental units or guest baths that see light use, but it tends to chalk and show hairline cracks around the drain within five to eight years. Solid-surface panels in a faux marble or subway-tile pattern look the most like custom tile and resist impact well, though a 60-inch back wall can weigh 80 pounds or more and needs two people.

Measuring and Sizing the Alcove

A standard alcove tub is 60 inches long, and depths of 30 and 32 inches are the most common. Measure before the old tub comes out, then measure again after demolition, because walls are rarely square.

1. Measure the back wall width at the floor, 36 inches up, and 72 inches up. Use the smallest number.
2. Measure depth from the back wall to the front edge of the tub apron on both ends.
3. Check plumb on each end wall with a 4-foot level. If walls are out more than 1/4 inch over their height, plan to shim studs.
4. Note the drain location: left, right, or center, measured from the end wall.
5. Check ceiling height. Wall panels usually run 72 to 78 inches above the base.

Order a base with the drain on the side you want. Left- and right-hand versions are not interchangeable on end-drain models. Center-drain bases give you more freedom but always require moving the original tub drain, which sits at one end.

The Drain Move and Other Plumbing Changes

This is where DIY projects succeed or stall. A bathtub drain sits at one end, close to the wall, with an overflow above it. A shower base drain sits either at an end or in the center, farther from the wall. In nearly every conversion, the drain has to shift somewhere between 3 and 15 inches.

On a slab foundation, that means breaking concrete with a rotary hammer, cutting the existing PVC or cast-iron line, and re-routing with a new P-trap. Plumbers generally charge $600 to $1,800 for slab work. Over a crawl space or basement, it is far easier: open the subfloor, extend the line, and install a new trap, usually $250 to $700 in labor.

Code matters here. The International Residential Code calls for a minimum 2-inch drain on showers, while many older tub drains are 1-1/2 inch. Some jurisdictions allow the smaller line for a replacement, but many inspectors will require upsizing. Also plan the valve: tubs use a tub-and-shower valve with a spout, and you will want to cap the spout outlet and ideally raise the showerhead arm to 80 inches for taller users. Swapping to a pressure-balancing or thermostatic valve at the same time costs $150 to $450 for the valve body, and it prevents scalding when someone flushes a toilet.

Step-by-Step Installation Overview

A competent DIYer with plumbing experience can finish a basic conversion over two or three weekends. Here is the typical sequence.

1. Demolition: Shut off water, remove the surround or tile down to studs, disconnect the drain and overflow, then cut or lift out the tub. Steel tubs weigh 60 to 120 pounds; cast iron can top 300 pounds and is usually broken in place with a sledge.
2. Framing prep: Add 2×6 blocking at 34 to 38 inches for future grab bars, sister any damaged studs, and shim walls flat.
3. Plumbing rough-in: Relocate the drain, set the new drain body height to match the base, and update the valve.
4. Set the base: Most manufacturers call for a mortar bed of sand mix or a specified foam underneath so the pan does not flex. Level it in both directions and screw the flange to studs.
5. Install walls: Dry-fit panels, cut valve and head holes with a hole saw, then bond with the manufacturer’s adhesive and fasten through the flanges.
6. Finish: Patch drywall above the surround, caulk with 100 percent silicone, and hang the door.

Budget 24 hours for adhesive and mortar to cure before anyone showers. Many acrylic manufacturers void warranties if the base is set without full support underneath, so follow the exact bedding method in the instructions.

Choosing a Door or Screen

A 60-inch opening gives you three practical options. Sliding bypass doors with 1/4-inch tempered glass cost $250 to $900 and work well in tight bathrooms because nothing swings into the room. Frameless sliders with 3/8-inch glass look cleaner and run $700 to $1,800. A fixed half-screen with an open entry costs $300 to $900 and suits walk-in layouts, though some water will escape unless the showerhead is at the far end.

Whatever you choose, confirm the threshold of your base is compatible. Some low-profile bases have a sloped front lip that needs a specific door track.

Total Cost: DIY vs. Professional Install

Here is how a typical project adds up:

• DIY with a mid-range acrylic kit: $1,500 to $3,000 including drain, valve, door, adhesives, and a plumber for the drain move only.
• Handyman or general contractor: $3,500 to $6,500 installed.
• Bath remodeling company: $6,000 to $12,000, often with a one-day install and lifetime warranty on their proprietary panels.

Unexpected costs usually come from what is hiding behind the old tub. Rotted subfloor around the drain ($300 to $1,200 to repair), mold in the wall cavity, or a corroded galvanized supply line can show up once walls are open. Keep 15 percent in reserve.

Common Mistakes That Lead to Leaks

Most failed conversions share the same few errors. Setting the base without a full bed of support causes flexing, which cracks the drain seal and eventually the pan. Running wall panels past the base flange instead of lapping them over it lets water wick behind the surround. Sealing with painter’s latex caulk instead of silicone results in mildew and gaps within a year. And skipping a 1/8-inch gap between panel bottoms and the base prevents caulk from bonding properly.

One more tip: if anyone in the home has limited mobility, choose a base with a threshold of 2 inches or less, or a true barrier-free base with a collapsible water dam. Upgrading now costs far less than retrofitting later.