A small bathroom works when every fixture keeps its clear space: 15 in from the toilet’s centerline to anything beside it and 21 in of clear floor in front of the toilet and the sink. With those, a half bath fits in 2 ft 6 in × 6 ft 9 in, a 3/4 bath with a 32 in shower in 5 ft 3 in × 6 ft, and a full bath with a 60 in tub in 5 × 7 ft. A 5x8 is the most common small full bath and the easiest to plan.
How small can a bathroom be?
The code doesn’t set a minimum room size for a bathroom; the fixtures and their clear spaces do. We asked the layout planner for the smallest room that holds each kind of bathroom with an elongated toilet, a 24 in vanity and a 30 in door, trying room sizes in 3 in steps:
| Bathroom | Smallest room | How it’s laid out |
|---|---|---|
| Half bath: toilet and sink | 2 ft 6 in × 6 ft 9 in (17 sq ft) | Toilet and vanity facing each other from the short walls, the door in the long wall between them |
| 3/4 bath: toilet, sink and a 32 × 32 in shower | 5 ft 3 in × 6 ft (31½ sq ft) | Shower and toilet side by side, the vanity facing them |
| Full bath: toilet, sink and a 60 × 30 in tub | 5 ft × 6 ft 9 in (34 sq ft) | Tub along the long wall, toilet and vanity facing each other beside it |
Every room passes the 2021 International Residential Code’s clearances and leaves a way in from the door, which swings into the room. A 24 in door takes the half bath down to about 2 ft 6 in × 6 ft 3 in. These are the least that work, not what we’d build: the plans below have more room.
For a half bath, the half bath dimensions page has the smallest sizes for each layout, and powder room layouts draws the tiny ones. How bathrooms are counted as full, 3/4 and half: what is a 3/4 bathroom.
Eight small bathroom layouts, drawn to scale
The dashed boxes are the clear spaces the code asks for, and the brass line marks the toilet’s centerline. Open any plan in the planner to move things, change the door or switch to centimeters.
- Clear in front of the vanity: 27 in
- Sink centerline to the side: 18 in
- Toilet centerline to the side: 18 in
- Clear in front of the toilet: 27 in
3x5: a powder room under the stairs
Fifteen square feet is enough for a toilet and a sink only if both hang on the wall. A wall-hung toilet sticks out about 21 in instead of 30, and an 18 in wall-mounted sink about 12 in, so they can face each other across the 5 ft length with 27 in between. Each sits on the middle of a 3 ft wall, 18 in from its centerline to either side.
- Door: 24 in, in the middle of a long wall.
- Watch for: a wall-hung toilet needs a carrier in a 2×6 wall; plan that with a plumber.
- Clear in front of the vanity: 39 in
- Sink centerline to the side: 39 in
- Toilet centerline to the side: 15 in
- Clear in front of the toilet: 30 in
5x7: a full bath with a narrow vanity
The 60 in tub fills the 5 ft end. The 54 in of wall beside it holds the toilet and an 18 in vanity: the toilet’s centerline 15 in from the end wall, then 21 in to the vanity, with the toilet and the sink 30 in apart, center to center. A 24 in vanity doesn’t fit on this wall. More options in the 5x7 bathroom layouts.
- Door: the end wall opposite the tub.
- Watch for: the toilet sits at the code’s 15 in from the wall; there’s no room to slide it over.
- Toilet centerline to the side: 18 in
- Clear in front of the toilet: 30 in
- Clear in front of the vanity: 39 in
- Sink centerline to the side: 15 in
5x8: the classic small full bath
One more foot changes a lot: the 66 in beside the tub takes the toilet with 18 in on each side and a 30 in vanity, all on one plumbing wall. This is the layout most hall baths use. Three versions are drawn in the 5x8 bathroom layouts.
- Door: the end wall opposite the tub.
- Watch for: a vanity wider than 36 in won’t fit beside the tub.
- Clear in front of the shower: 64 in
- Toilet centerline to the side: 18 in
- Clear in front of the toilet: 30 in
- Clear in front of the vanity: 39 in
- Sink centerline to the side: 16 in
5x8 with a walk-in shower
A 60 × 32 in shower base goes where the tub was, so the toilet and the drains stay put. The shower door goes at the end away from the toilet, where 64 in of floor runs to the far wall.
- Door: the end wall opposite the shower.
- Watch for: the base is 2 in deeper than a 30 in tub, which leaves room for a 24 in vanity with 18 in beside the toilet.
- Clear in front of the shower: 36 in
- Toilet centerline to the side: 15 in
- Clear in front of the toilet: 21 in
- Clear in front of the vanity: 21 in
- Sink centerline to the side: 15 in
6x6: a corner shower, toilet and vanity
A square 6 ft room has more floor than a 5x7 but less straight wall. The shower takes a corner, the toilet goes beside it at the code’s 15 in, and a 24 in vanity faces the toilet from the opposite wall with 21 in between them. The toilet’s side room, the floor between the toilet and the vanity, and the sink’s distance to the wall are all at the code minimum. More plans in the 6x6 bathroom layouts.
- Door: the side wall below the shower.
- Watch for: a 30 in vanity doesn’t fit here; neither does a 36 in one.
- Clear in front of the vanity: 51 in
- Sink centerline to the side: 45 in
- Toilet centerline to the side: 18 in
- Clear in front of the toilet: 42 in
6x8: room for the roomier numbers
At 6 ft wide, everything in front of the fixtures opens up: 42 in in front of the toilet and 51 in in front of the vanity. The toilet gets 18 in on each side, and this plan meets every roomier designer number. A 60 in tub across the 6 ft end leaves 12 in beside it for a shelf. More in the 6x8 bathroom layouts.
- Door: the long wall facing the fixtures.
- Watch for: nothing tight. A 36 in vanity fits too, with the toilet 15 in from the end wall.
- Clear in front of the shower: 48 in
- Clear in front of the vanity: 63 in
- Sink centerline to the side: 21 in
- Toilet centerline to the side: 18 in
- Clear in front of the toilet: 54 in
7x7: a square room with a big shower
A 7 ft square takes a 48 × 36 in shower in one corner, the toilet beside it on the same wall and a 36 in vanity on the next wall, with every roomier designer number met. Square rooms have their own guide: square bathroom layouts.
- Door: the corner across from the shower.
- Watch for: the shower opening and the vanity share the open floor in the middle, and a hinged shower door swings out into it.
- Clear in front of the vanity: 39 in
- Sink centerline to the side: 21 in
- Toilet centerline to the side: 21 in
- Clear in front of the toilet: 30 in
5x10: long and narrow
In a long room, line everything up along one wall and keep the walkway on the other side: the vanity by the door, the toilet in the middle, 21 in from the vanity and 30 in from the tub, and the tub across the far end. More plans for these rooms in long narrow bathroom layouts.
- Door: the end wall, opposite the tub.
- Watch for: don’t put the door in the middle of the long wall: it swings across the walkway.
Space savers that work
- A pocket or outswing door. A 30 in door that swings in sweeps a 30 in quarter circle of floor; the planner shows when that sweep is what keeps a layout from fitting.
- A wall-hung toilet. About 21 in from the wall to the front of the bowl (Kohler Veil), against about 30 in for a floor-mounted elongated toilet. It needs a 2×6 wall for its carrier.
- A compact elongated toilet. An elongated seat in the space of a round one: 27¾ in from the wall on Kohler’s Santa Rosa.
- A shallow vanity or a wall-mounted sink. Shallow vanities are about 18 in deep (Kohler Hearthaven) and wall-mounted sinks about 12 in, against 21 in for a standard vanity.
- A corner sink. For scale, Kohler’s Marston corner sink, now discontinued, took 16 in along each wall and came 20⅜ in out from the corner. Check the spec sheet of the one you buy.
- Storage off the floor. A recessed medicine cabinet, a shower niche or shelves above the toilet don’t touch the clear spaces.
Five mistakes that make a small bathroom fail
- The door hits a fixture. Check the swing before anything else; a pocket door or an outswing door often saves the plan.
- The toilet sits too close to a wall. 15 in from its centerline to a wall, a tub or a vanity is the code minimum (IRC R307.1); a toilet tucked closer fails inspection.
- No room in front. 21 in of clear floor in front of the toilet and the sink, 24 in in front of a shower opening.
- The sink crowds the toilet. A toilet and a sink side by side need 30 in from center to center (IRC P2705.1), even with a vanity cabinet between them.
- No way through. Two fixtures can each have their clear space and still leave no path between them; the planner checks that you can get from the door to each one.
Questions people ask
What is the smallest size for a bathroom?
With an elongated toilet, a 24 in vanity and a 30 in door, about 2 ft 6 in × 6 ft 9 in for a half bath, 5 ft 3 in × 6 ft for a 3/4 bath with a 32 in shower, and 5 ft × 6 ft 9 in for a full bath with a 60 in tub. The code sets clearances, not a minimum room size.
How do you lay out a small bathroom?
Start from the wall with the plumbing, settle the door and its swing, put the tub or shower in first, then fit the toilet and the vanity with 15 in beside the toilet’s centerline and 21 in in front of each. The layout planner tries every arrangement for your room.
Can you fit a tub in a small bathroom?
A 60 × 30 in tub needs a 5 ft wall to fit end to end. In a 5x7 it leaves room for the toilet and an 18 in vanity; in a 5x8, for a vanity up to 36 in.
What size is a small bathroom with a shower?
From about 5 ft 3 in × 6 ft with a 32 × 32 in shower. A 5x8 with a 60 × 32 in shower base, a 6x6 with a corner shower or a 7x7 with a 48 × 36 in shower all work, as drawn above.
Is a 5x8 bathroom small?
It’s the most common small full bath: 40 sq ft, with the tub across the 5 ft end and the toilet and vanity on one long wall. See the 5x8 bathroom layouts.
Sources
- 2021 International Residential Code, chapter 3 (R307.1 fixture clearances, R305.1 ceiling height) and chapter 27 (P2705.1 fixture spacing, P2708.1 showers), read in Colorado’s adoption without amendments on UpCodes
- Larimer County, Colorado: Figure R307.1 bathroom clearances
- NKBA’s free bath planning guidelines: the roomier spacing (18 in beside a toilet, 20 in beside a sink, 36 in between two sinks, 30 in in front of each fixture, a 36 × 36 in shower, a 32 in door opening, a 36 × 66 in toilet compartment). Its newer, paid editions change some numbers.
- Kohler Underscore alcove tubs, 60 × 30 in and 60 × 32 in spec sheets
- Toilet depths from the wall: Kohler Cimarron round and elongated spec sheets
- Kohler Veil wall-hung toilet spec sheet: 21 in from the finished wall to the front of the bowl
- Kohler Santa Rosa compact elongated toilet spec sheet: 27¾ in from the wall to the front of the bowl
- Kohler Hearthaven 36 in vanity spec sheet: 18-1/16 in deep
- Kohler Marston corner sink spec sheet (the sink has since been discontinued): 16 in along each wall, 20⅜ in from the corner to the front edge
Checked October 19, 2026. The smallest sizes and all plans were worked out with the BathDraft layout planner; centimeters are converted from inches. Typical bathroom sizes by type are on our standard bathroom size page.