Measure the bathroom and pick what goes in it. You see whether it fits with the clear space the NKBA recommends (or only the code minimum), where the toilet, vanity, tub or shower and the door go, the biggest vanity your room takes and where the toilet drain sits. Then open a bathroom in the free planner and arrange the rest.
Your bathroom
Toilet, sink and tub: fits comfortablytub on one 5′ wall · toilet on the other 5′ wall · 36″ vanity on one 8′ wall · door on the other 8′ wall
What else fits this room
Quick answer: a bathroom layout works when the toilet’s centre is 18″ from anything beside it (15″ is the code minimum), every fixture has 30″ of clear floor in front of it (21″ by code, 24″ at a shower), and a sink’s centre is 20″ from a side wall (15″ by code). By those rules a full bath with a tub needs 5′ × 7′ at code minimums, and the standard 5′ × 8′ gives the space the NKBA recommends.
How to use the bathroom layout planner
- Measure the room wall to wall, both ways, from the finished walls (tile included).
- Pick a tub, a shower, both or neither, and one sink or two. The answer says whether it fits with the recommended space or only the code minimum, where each fixture and the door go, the biggest vanity the room takes and where the toilet drain sits. The list under it shows what else your room takes.
- Open it in the free planner to try your own fixtures, the storage and the finishes, drawn to scale. Copy link keeps the result.
The rules of a bathroom layout
These are the National Kitchen & Bath Association’s Bathroom Planning Guidelines. Each gives what the NKBA recommends and, in brackets, the minimum the International Residential Code requires.
- Toilet: its centreline at least 18″ (15″) from any wall, fixture or other obstacle on either side, so a toilet takes a 36″ (30″) wide space. The drain sits 12″ out from the finished wall behind it: the standard rough-in.
- Clear floor in front: 30″ (21″) from the front of the toilet, the sink and the tub to whatever is opposite, and 30″ (24″) at a shower’s entry. Clear spaces may overlap each other.
- Sink: its centreline at least 20″ (15″) from a side wall or a tall obstacle such as a shower. Two sinks: their centrelines 36″ (30″) apart.
- Shower: at least 36″ × 36″ (30″ × 30″) inside, with an opening at least 22″ wide.
- Door: a 32″ clear opening, which takes a 2′10″ door; a 2′0″ door only where the walls leave no choice. No door may swing into a fixture.
The fixtures as the planner draws them: a toilet 20″ wide and 30″ from the wall to the front of the bowl (standard toilets are 28–30″ deep), a standard alcove tub 60″ × 30″, vanities 21″ deep in the usual widths (24″ to 48″ with one sink, 60″ or 72″ with two), and a compact 24″ vanity 18″ deep for a powder room.
Minimum bathroom sizes
The smallest room, in whole feet, that takes each bathroom with its door, found by the planner above:
| Bathroom | Code minimums | NKBA recommended |
|---|---|---|
| Half bath: toilet and sink | 3′ × 6′ | 4′ × 7′ |
| Shower bath: toilet, sink and shower | 4′ × 7′ | 5′ × 8′ |
| Full bath: toilet, sink and tub | 5′ × 7′ | 5′ × 8′ |
| Full bath with two sinks | 5′ × 9′ | 5′ × 10′ |
| Tub and a separate shower | 5′ × 8′ | 5′ × 11′ |
| Tub, separate shower and two sinks | 5′ × 11′ | 7′ × 10′ |
Three worked examples
The standard 5′ × 8′ full bath. It fits with the NKBA’s recommended space: the tub across one 5′ end, the toilet on the other, a 36″ vanity on one long wall between them and the door opposite it. The toilet’s centre is 18″ from the wall beside it and every fixture has at least 36″ of clear floor in front.
A 4′ × 5′ powder room. A toilet and a 24″ compact vanity fit at the code minimums, with a 2′0″ door swinging in. For the recommended space it needs about 1′ 6″ more length or 1′ 2″ more width.
An 8′ × 10′ primary bathroom. A tub, a separate 36″ shower and a 72″ double vanity all fit with the recommended space: the shower and tub on one 10′ wall, the toilet and vanity on the other, the door on an 8′ wall. The tub’s open end needs a short wall, as every alcove tub does.
Common bathroom layout mistakes
- Measuring the toilet from its tank. The 15″ and 18″ are from the toilet’s centreline, the line through its drain, to whatever is beside it: a wall, a vanity or a tub.
- Forgetting the door. The code does not let a door swing into a fixture (IRC P2705.1.6), and a door is often what a small bathroom has no room for. Where it cannot swing in, hang it to swing out, or fit a pocket door.
- Ordering the toilet before checking the rough-in. Measure from the finished wall to the centre of the drain: 12″ in most homes, 10″ or 14″ in some older ones. A toilet for the wrong rough-in does not fit.
- Two sinks in a 5′ × 8′ bath. Two sinks need their centres 30–36″ apart, so the smallest double vanity is 60″. With a tub, that does not fit a 5′ × 8′ room even at the code minimums; it takes 5′ × 9′.
- A shower smaller than 36″. 30″ × 30″ inside passes the code and leaves little room to turn round; the NKBA recommends 36″ × 36″.
Then size the pieces: the bathroom vanity height and mirror size calculator for the vanity and the mirror over it, and the bathroom remodel cost calculator for what the new layout will cost.
Plan the whole bathroom: the free 2D room planner opens with a furnished bathroom you can resize and rearrange, drawn to scale.
Open a bathroom in the plannerRead next
- 11 small bathroom ideas that change the space
- Small bathroom makeovers that prove square footage isn’t the problem
- Small powder room ideas for limited spaces
- Walk-in shower ideas
- Soaking tub and shower combos
Bathroom layout questions
How much space do you need for a toilet?
A space 36″ wide (18″ each side of its centreline) with 30″ of clear floor in front, as the NKBA recommends. The building code’s minimum is 30″ wide (15″ each side) with 21″ in front. With a toilet 30″ deep, that is about 60″ from the wall behind it to whatever is opposite, or 51″ at the minimum.
What is a toilet rough-in?
The distance from the finished wall behind the toilet to the centre of its drain. It is 12″ in most homes and 10″ or 14″ in some older ones. Measure it before you buy: a toilet is made for one rough-in and does not fit the others.
How far should a toilet be from the wall?
Its drain is 12″ from the wall behind it (the standard rough-in). To the side, its centre should be at least 15″ from a wall, a vanity or a tub by code, and 18″ as the NKBA recommends.
What is the minimum size for a bathroom?
With a toilet, a sink and a tub, 5′ × 7′ meets the code minimums and 5′ × 8′ gives the NKBA’s recommended space. A half bath with a toilet and a sink fits in 3′ × 6′ at the minimums; 4′ × 7′ is comfortable. The chart above gives the size for every combination.
What are half bath dimensions?
At least 3′ × 6′ for a toilet and a compact sink at the code minimums, usually with the door swinging out or a pocket door. For the NKBA’s recommended space, about 4′ × 7′. A 4′ × 5′ powder room works at the minimums.
What is the best layout for a small bathroom?
In a 5′ × 8′ bathroom: the tub across one 5′ end, and the toilet and vanity on the long wall or the toilet on the far end, with the door opposite the vanity so it swings over the floor, not into a fixture. The planner above tries every arrangement and shows the one that fits best.
What size is a standard bathtub?
60″ long and 30–32″ wide, for an alcove between two walls: the 5′ end of a 5′ × 8′ bathroom exists because of it. Give it 30″ of clear floor in front (21″ by code).
Is there a free bathroom layout planner?
Yes: the calculator above checks your room against the NKBA’s clearances, and the free 2D room planner opens a furnished bathroom to scale that you can resize, rearrange and save, with no download.