| Compact alcove, 4 ft | About 48 × 30–32 in (122 × 76–81 cm) | Usually one-person, reclined or semi-reclined | Very tight bathrooms or replacement projects with limited wall length | Shorter bathing well; check interior length and seat position, not just the exterior footprint. |
| Compact alcove, 4½ ft | About 54 × 30–32 in (137 × 76–81 cm) | One-person; commonly a molded seat or sloped back | Bathrooms that need more bathing room than a 4 ft tub but cannot fit a standard 5 ft tub | Confirm the rough opening, drain location, apron, and access panel requirements. |
| Standard alcove, 5 ft | About 60 × 30–32 in (152 × 76–81 cm) | One-person; left- or right-hand drain options are common | A compact full-length tub for a typical three-wall alcove | Often the easiest format to compare for replacement; verify the finished opening and plumbing position. |
| Compact drop-in | About 54–60 × 30–36 in (137–152 × 76–91 cm) | One-person; deck-mounted installation | Bathrooms with a planned platform or tiled surround | Allow space for the deck, pump, service access, and supporting structure; the finished footprint exceeds tub dimensions. |
| Small corner bath | About 48 × 48 in (122 × 122 cm); shape varies | Usually one-person; some designs offer a corner seat | Rooms where a corner installation works better than a long alcove tub | Check the diagonal reach, entry clearance, and whether the corner footprint obstructs nearby fixtures. |
| Compact freestanding | About 55–60 × 27–31 in (140–152 × 69–79 cm) | One-person; typically centered or offset drain | Bathrooms prioritizing a freestanding look and open access around the tub | Include clearance for cleaning and plumbing; confirm floor loading and pump service access. |