Moving the plumbing
Keeping the valve and drain exactly where they are is the single biggest cost lever in this project. Moving either one runs $80 to $200 per line, and a full relocation of the supply and drain lines together can run into the low thousands once wall or floor work is included.[1]
A new location for the shower head or a second valve for a handheld sprayer counts as moved plumbing too, even if the main drain stays put.
What's behind the wall
A base quote assumes the wall and subfloor behind the old tub are sound. Rot, mold or corroded old pipework found once the tub is out gets priced separately, and it's the most common reason a final bill runs above the original quote.
Homes built before the 1980s are more likely to turn up galvanized supply lines or cast iron drains that a contractor may recommend replacing while the wall is already open, which adds to the job even though it wasn't the original scope.
Surround choice and glass
Moving from an acrylic kit to custom tile roughly doubles or triples the surround cost on its own, since tile adds a waterproofing step and per-piece labor that a one-piece kit skips entirely.[2]
A frameless glass door costs roughly two to three times a framed door's price, driven by thicker glass and hardware built specifically for that opening rather than off a standard size.[2]
Permits and access
Permit fees vary by city and aren't part of most national cost ranges, so budget for that as a separate line rather than assuming it's baked into a contractor's quote.
A bathroom on an upper floor, or one reached through a narrow hallway or stairwell, can add labor time for material handling and protecting the path, which some contractors price as a modest access fee.
Labor rates in your specific metro
Tile and stone setters, the trade behind most of a conversion's finish work, earn a median $23.52 an hour nationally, but that figure spans a wide range: the bottom 10% of the trade earns under $15.93 an hour, while the top 10% earns over $38.48.[3]
A metro on the high end of that spread will price the same custom tile job higher than a metro on the low end, independent of anything about the specific bathroom. This site's local estimate accounts for that gap; a flat national number can't.
Timing and scheduling
A contractor booked out several months tends to quote closer to the top of a range, since demand for their time is already high; one with an open schedule may price more competitively to fill it.
Rushing a job, asking for a start date days away during a contractor's busy season, can also push a quote higher, since it may require paying overtime or pulling a crew off another job.