Standard Shower Pan and Base Sizes: The Full Size Chart

A base that is 2 in. too wide stops a project for a week; a base whose drain sits on the wrong side means cutting the subfloor. Standard shower pan sizes solve most of that problem, but only if you measure the finished opening rather than the space you see before the walls are closed. This chart runs through the footprints that actually ship, what each one fits, and how to confirm a size before you order.

The Common Base Footprints and What They Fit

Almost every standard base sold in the United States falls into one of two families: a rectangular alcove base sized for a tub-to-shower conversion, and a square or near-square base for a corner or neo-angle stall. The alcove family clusters around a 60 in. width because that is the length of the tub the base usually replaces. Depth then decides how much floor space the shower gives up.

MCOCOD shower bases follow that pattern with a limited option set: SMC bases with edges are offered in 60 in. x 30 in., 60 in. x 32 in., 60 in. x 34 in. and 60 in. x 36 in., the centre-drain version adds 48 in. x 32 in. and 48 in. x 36 in., and the acrylic solid-surface bases come in 60 in. x 30 in. and 60 in. x 32 in. Each of those is available in left-drain, right-drain or centre-drain form, which matters more than most buyers expect at the ordering stage.

Measuring Your Opening Against the Standard Sizes

A base is set between finished surfaces, so the number that decides fit is the finished opening, not the stud-to-stud measurement. Take the width at three heights - a few inches above the floor, at mid-height, and just below where the wall covering ends - and use the narrowest reading. Do the same for depth from the back wall to the front plane of the curb or wall return. If the two readings differ by more than about 3/8 in., the opening is out of square and a standard base will leave a tapered caulk joint at one end.

With-edges bases change this calculation: the moulded flange tucks behind the wall covering, so the setting bed is measured to the studs while the visible base still lands inside the tiles. Confirm which construction you are buying before you cut anything, then verify the pan is level in both directions before the drain connection is made.

Width, Depth and the Door That Sits on Top

Door sizing follows the base, not the other way around. A 60 in. base pairs with a 60 in. wide door model, and the panel layout inside that opening depends on how the glass moves. A single sliding door leaves a narrower clear entry because the sliding panel parks in front of a fixed panel; a double sliding door splits the travel across two panels and needs enough track length for the overlap in the middle.

Depth decides which configurations are practical. A 30 in. deep alcove is workable with a single sliding or pivot door but leaves little floor to stand on once the door swings inward. At 36 in. deep, hinged and pivot doors become comfortable, which is why alcove footprints over 32 in. are often specified with a swing door plus a fixed panel. The door series MCOCOD lists at a 60 in. width - DS01, DS13, SS04, SS05, SS08 and SS13 - are all sliding or soft-closing sliding designs, so a swing door usually means a custom configuration.

Whatever sits on the base, the glass itself is safety glazing in a wet area: US federal rules for architectural glazing products are set out in 16 CFR Part 1201, and MCOCOD states tempered glass with SGCC certification for its shower doors. Thin or non-tempered panels have no place in a tiled shower, and glass thickness also sets which hinge and clamp families can be used.

Drain Position: Centre, Offset, Left and Right

Drain location is the constraint that turns a cheap base swap into a plumbing job. The outlet in the pan has to sit directly over the trap or the subfloor opening, and the pan itself is not movable once it is set. Work out where the existing drain is before you choose, then decide whether the pan or the plumbing gives way.

Centre-drain pans are symmetrical and suit new construction where the trap can be placed freely. Left and right drain pans exist so a pan can drop over an existing tub drain, which is almost never centred. Offset drains are the compromise when the trap is near one end but not against the wall. If the trap needs to move, expect to open the subfloor and to confirm the joist direction first; a drain that has to cross a joist is a different job from one that runs alongside it. The shower bases collection lists drain orientation as a selectable option for this reason.

Local plumbing and building codes govern the receptor, the trap and the connection, so the pan cannot be treated as a purely decorative choice; the ICC publishes the model codes most US jurisdictions adopt at iccsafe.org. Check the local amendment before setting a pan on a subfloor that has been cut for a relocated drain.

When No Standard Size Fits Your Opening

Standard sizes cover tub replacements and typical stalls. They do not cover a 55 in. alcove, an opening that has been re-tiled to a different depth, or a corner stall where the door wall sits at 45 degrees. In those cases the practical choice is a made-to-measure pan rather than a compromise pan with wide filler strips, because filler joints at the base are where water finds its way into the framing.

Ordering a custom pan is mostly a measurement exercise: finished opening width at three points, depth at both ends, wall construction, curb height, drain centre measured from two reference walls, and the intended door configuration. MCOCOD produces made-to-measure work from supplied measurements and issues drawings for confirmation before fabrication. A non-standard dimensions enquiry starts with those numbers, and it is worth taking photos of the opening with a tape visible in frame. Custom sizes also allow glass thickness and hardware to be matched to the pan at the same time, so the door and base arrive as one system rather than two guesses.

Nominal vs Actual Dimensions: Reading the Specification

The size in a product title is usually nominal. A pan described as 60 in. x 32 in. may measure slightly differently across the outer edge, and it may be tiled-in or surface-mounted. Two measurements matter: the outside dimension of the moulded pan, and the dimension of the setting area between finished walls. Read both from the specification rather than assuming the title is a cut-to size.

Material tolerances and test methods for these components are published by standards bodies such as ASTM International, which is where a specifier looks when a submittal is required. Pans are also formed with a slope toward the drain so the floor clears itself; the usual figure is a quarter inch of fall per foot, which is why the pan looks shallow at the drain and deeper at the perimeter. Verify the pan you receive is not dished the wrong way before setting it, and keep the level check running front to back as well as side to side, because a pan that is level but twisted will not drain cleanly and cannot be corrected after the setting bed cures. On a tiled installation, the wall-to-pan junction and any substrate behind the tile follow the waterproofing practice described by the Tile Council of North America and the assemblies catalogued by the Whole Building Design Guide.

Accessible and Low-Threshold Footprints

Accessible and barrier-free installations are a different specification, not a smaller version of a standard pan. The ADA Standards for Accessible Design describe transfer and roll-in shower compartment sizes, seat requirements and grab bar locations; a 60 in. x 30 in. pan meets none of those requirements on its own. Treat standardisation and accessibility as two separate checks.

What a low-threshold base can do is reduce the step-over to a few inches, which helps for aging-in-place remodels where full compliance is not the goal. That version still needs the same measurements and the same drain discipline, and pairing it with a WaterSense-labelled showerhead keeps water volume and splash inside the smaller footprint. Where the project has to meet accessible design requirements, confirm the current ADA provisions and any state or local amendment before ordering anything, and note that MCOCOD's published range does not claim accessibility compliance.