The base numbers
HomeAdvisor's national range for this project runs from $1,500 on the low end to $8,000 on the high end, averaging close to $3,000, with labor accounting for 40% to 60% of whatever that total turns out to be.[1]
That range compresses or stretches almost entirely based on which surround you pick. An acrylic panel kit runs $2,000 to $5,000 installed. A one-piece fiberglass unit runs a bit more, $4,000 to $8,000. A custom ceramic tile shower runs $6,000 to $12,000.[2]
Removing what's there
Tub removal alone typically costs $150 to $300, a small line item but a mandatory first step regardless of what replaces the tub.[3]
Wall cleanup or minor repair around the old tub adds $300 to $800 in a straightforward case; more extensive repair, if the wall has water damage, is priced once the contractor can see it.
Add-ons, one at a time
A framed glass door adds $300 to $1,200; a frameless door adds $900 to $2,300, largely because frameless glass is thicker and needs custom-fit hardware.[2]
A built-in bench adds $100 to $500. A recessed niche for shampoo and soap typically adds a similar $200 to $500.[2],[4]
Moving the valve or drain to a new spot costs $80 to $200 for each supply or drain line that has to relocate, so a move involving two or three lines can add several hundred dollars on its own.[3]
Putting it together
A budget-focused conversion, acrylic kit with the plumbing left in place, lands near the bottom of the range: roughly $2,000 to $5,000 all in.
A fuller build, custom tile with a frameless door and a niche, and the drain moved, stacks the custom tile base with each add-on's cost, which is why it can land closer to $9,000 to $15,000 once everything is totaled.
How labor share changes the math
Because labor is 40% to 60% of the total, the same surround choice can price differently from one metro to the next, even before add-ons enter the picture.[1]
A city where tile and stone setters earn well above the $23.52 national median hourly wage will generally see higher installed quotes for the same custom tile job than a city where wages sit closer to, or below, that median.[5]
That's the whole reason this site runs a city-by-city estimate rather than repeating one flat national range on every page: the underlying material and add-on costs are national, but labor is local.
A note on quotes that fall outside these ranges
A quote well below the low end of a range here is worth a second look; it may exclude demolition, permits, or the waterproofing step, rather than being an unusually good deal.
A quote above the high end isn't automatically a bad sign either, especially in a high-wage metro or on a bathroom with tricky access, but it's a reasonable prompt to ask the contractor to walk through their breakdown line by line.