Field guide · Bath

Bathroom layouts & clearances

A bathroom is the one room where the fixtures are nearly fixed sizes and the room is nearly a fixed size, so the whole design is a packing problem. Here are the pieces, the gaps they need, and the four layouts that keep coming out of the arithmetic.

01

The fixtures

FixtureFootprint (W × D)Notes
Toilet20 × 28″elongated; round-front is ~26″ deep
Alcove tub60 × 30–32″the number the whole room is built around
Freestanding tub60–66 × 30–32″needs air on all sides — see §04
Shower, minimum32 × 32″code floor; feels like a phone booth
Shower, comfortable36 × 36″the size to aim for
Shower, tub replacement60 × 32″drops straight into the old alcove
Vanity, single24 / 30 / 36 / 48 × 21″depth is 21–22″ almost universally
Vanity, double60 / 72 × 21″under 60″ and the two sinks fight
Pedestal sink24 × 20″buys floor space, costs all storage
02

Clearances: code floor vs comfortable

Two different sets of numbers circulate, and conflating them is why some bathrooms are legal and miserable. The IRC is the minimum a building official will pass. The NKBA planning guidelines are what a designer aims for.

ClearanceCode minimumRecommended
In front of toilet21″30″
Toilet centerline to any wall or fixture15″18″
In front of sink / vanity21″30″
In front of a shower opening24″30″
Shower interior30 × 30″ / 900 sq in36 × 36″
Ceiling over shower / tub80″—

The 15″ rule does the most work. It is measured from the centerline of the toilet outward in both directions — so a toilet needs a 30″-wide clear bay minimum, 36″ to be pleasant. Squeezing one between a vanity and a wall is the single most common layout failure.

Verify locally. The IRC is amended jurisdiction by jurisdiction and remodels are treated differently from new construction. Treat these as the shape of the rule and your building department as the authority.

03

The room sizes these produce

BathroomSizeWhat fits
Powder / half bath3 × 6′toilet + small sink, door swinging out
Powder, comfortable4 × 5′toilet + 24–30″ vanity
Full bath, classic5 × 8′60″ tub across one end, toilet + vanity down the side
Full bath, easier5 × 10′same three fixtures with real elbow room
Primary, tub + shower8 × 10′separate shower, single vanity
Primary, full10 × 12′+double vanity, freestanding tub, water closet

The 5 × 8 is not a coincidence: a 60″ tub spans the short wall exactly, leaving a 60 × 60″ square for the toilet and vanity in a row. Almost every American three-fixture bathroom is that arithmetic.

04

Where these layouts go wrong

  • The door swing. A 30″ door sweeps a 30″ quarter-circle into the room, and in a 5 × 8 that circle overlaps the vanity or the toilet almost every time. Out-swinging or pocket doors are the usual rescue — and in a powder room, an out-swing may be the only way to meet the 21″ in front of the toilet.
  • Freestanding tubs need a perimeter. The sculptural look wants 6″ minimum behind and 4–6″ at the ends just to clean around, and a filler needs its own real estate. A 66″ tub is closer to a 78″ problem.
  • Vanity doors and drawers. The 30″ recommended in front is not slack — it's the drawer at full extension plus a person.
  • Double vanities under 60″. Two bowls in a 48″ top leaves no usable counter between them. One bowl and more counter wins.
05

Test it on the actual plan

Bathroom fixtures live in Poché's library at these footprints — toilet, tub, shower, vanity — with the clearances above attached, so placing one draws its real gap on your drawing. Put a toilet 14″ off a wall and it redlines; give it 15″ and it doesn't. The room either takes the layout or it doesn't, and you find out before the plumber does.

Try the layout on your own bathroom.

Upload the plan, set the scale, and drop the fixtures in at true size with their clearances drawn — free.

Try it on your plan →
More field guides All guides Kitchen clearances → Standard door sizes → Laundry room dimensions →