How to Create a Bathroom Floor Plan
A well-measured floor plan is the foundation of every successful bathroom remodel. Get the measurements wrong, and you'll end up with fixtures that don't fit, doors that hit the toilet, or code violations that fail inspection. This guide walks you through measuring your space accurately and creating a layout that works with your existing plumbing while meeting all clearance requirements.
Quick Summary
Time needed
2-4 hours
Difficulty
Moderate
Cost
Free - $50
Why Your Floor Plan Matters More Than You Think
Many homeowners skip the detailed floor plan step, assuming they can "eyeball it" or figure it out as they go. This is one of the most expensive mistakes you can make in a bathroom remodel. A floor plan isn't just a nice-to-have document—it's what prevents costly change orders, failed inspections, and that sinking feeling when you realize your new vanity blocks the door.
Here's what a proper floor plan enables:
- Accurate contractor bids: Contractors can give you firm quotes instead of estimates that balloon later.
- Permit approval: Most jurisdictions require scaled floor plans showing clearances for permit applications.
- Fixture ordering confidence: Know exactly what sizes will fit before you spend thousands on a vanity or shower enclosure.
- Plumbing cost control: Understanding existing drain locations helps you avoid expensive pipe relocations.
- Code compliance: Verify minimum clearances are met before construction, not during inspection.
Tools and Materials You'll Need
Creating an accurate floor plan doesn't require expensive equipment. Here's what to gather before you start:
Required
- 25-foot measuring tape
- Graph paper (1/4" grid)
- Pencil and good eraser
- Notepad for recording measurements
Helpful Extras
- Laser distance measure ($25-50)
- Smartphone for reference photos
- Floor plan software (see below)
- Helper to hold tape measure end
Critical Clearance Requirements
These are the minimum clearances required by most building codes. Memorize these numbers—they'll drive every layout decision you make. Note that some localities have stricter requirements, so always verify with your local building department.
Toilet Clearances
Center to side wall
Minimum distance from toilet centerline to any wall, vanity, or obstruction on either side
Front clearance
Minimum clear space in front of toilet to any wall, door, or fixture
Total width needed
15" on each side = 30" minimum total width for toilet space
Rough-in distance
Standard distance from wall to center of toilet drain (some toilets are 10" or 14")
Vanity/Sink Clearances
- 30"Minimum clearance in front of vanity
- 21"Standard vanity depth
- 18"Narrow vanity depth for tight spaces
- 4"Minimum from vanity edge to toilet center
Shower/Tub Clearances
- 30"Minimum shower interior dimension
- 24"Clearance in front of tub/shower entry
- 60"Standard tub length
- 32"Standard tub width
Step-by-Step: Creating Your Floor Plan
1. Measure the Overall Room Dimensions
Start by measuring the total length and width of your bathroom. Measure wall to wall at floor level, then measure again at counter height (about 36 inches). If the measurements differ by more than 1/4 inch, your walls aren't plumb—make a note of this, as it affects how fixtures fit.
How to measure accurately:
- 1. Hook the tape measure end on a corner or have someone hold it
- 2. Pull tape taut but don't stretch it
- 3. Read measurement at the wall surface, not the baseboard
- 4. Measure twice and record both readings
- 5. Note any alcoves, bump-outs, or irregular shapes
2. Locate and Measure Existing Plumbing
This is the most important step for controlling costs. Plumbing locations largely dictate your layout options because moving drains is expensive and disruptive.
For each drain and water supply, measure from two walls to pinpoint the exact location:
3. Map All Doors and Windows
Doors and windows create constraints that affect fixture placement. Document them thoroughly:
Door measurements
- - Width of door opening
- - Distance from corner to door frame
- - Swing direction (in or out)
- - Swing side (left or right)
- - Arc clearance needed (90-degree swing)
Window measurements
- - Width and height of opening
- - Distance from corners
- - Sill height from floor
- - Operation type (casement, double-hung)
- - Whether it's in shower zone
4. Draw the Room to Scale
Now transfer your measurements to paper or a digital tool. The standard scale for bathroom plans is 1/4 inch = 1 foot, which works perfectly with standard graph paper.
Graph Paper Method
- - Use 1/4" grid paper
- - 1 square = 1 foot at 1/4" scale
- - Draw walls as thick lines
- - Mark door swings as arcs
- - Indicate windows with parallel lines
- - Circle drain locations
Digital Tools
- - RoomSketcher (free basic plan)
- - Floorplanner.com (free)
- - SmartDraw (paid, powerful)
- - SketchUp Free (learning curve)
- - MagicPlan app (uses phone camera)
Include all walls, door openings with swing direction, windows, and existing plumbing locations in your base drawing. This becomes your template for trying different layouts.
5. Place the Toilet First
The toilet is always placed first because it's the hardest and most expensive fixture to relocate. The toilet drain is 3-4 inches in diameter and must maintain proper slope, making moves costly and complex.
Toilet placement rules:
- Keep it at or near the existing drain location if possible
- Ensure 15" minimum from centerline to any wall or obstruction
- Provide 21" minimum clear space in front (24-30" is better)
- Don't place directly in front of the door
- Consider privacy—avoid direct line of sight from hallway
Standard toilet dimensions for planning: approximately 28-30" deep and 18-20" wide. Draw a rectangle this size at scale on your plan.
6. Position the Shower or Tub
The shower or tub is placed second because its drain, while smaller than the toilet (2 inches), is still expensive to relocate. The shower also defines your primary wet zone.
7. Add the Vanity and Sink
The vanity is placed third because sink drains are the easiest to relocate (smaller pipe, easier access). This gives you the most flexibility in positioning.
Standard Vanity Sizes
- 24" wide: Small powder room
- 30-36" wide: Single sink, compact
- 48" wide: Single sink, comfortable
- 60-72" wide: Double sink
- 21" deep: Standard depth
- 18" deep: Narrow/compact option
Placement Considerations
- - 30" clearance in front minimum
- - Away from door swing path
- - Near natural light when possible
- - Electrical for lighting above
- - GFCI outlet within reach
For double vanities, ensure each sink has at least 30" of counter space (36" is better). Total width should be at least 60" for two people to use simultaneously.
8. Verify All Clearances and Traffic Flow
Before finalizing your layout, go through this verification checklist to ensure everything meets code and functions well in daily use:
Understanding Wet vs. Dry Zones
Professional bathroom designers think in terms of "wet" and "dry" zones. Understanding this concept helps you create a layout that's easier to maintain, better ventilated, and more functional.
Wet Zone
- - Shower interior and threshold
- - Bathtub and 2-foot splash radius
- - Area directly in front of shower entry
- - Requires waterproof surfaces
- - Needs excellent drainage slope
- - Benefits from dedicated exhaust ventilation
Dry Zone
- - Toilet area
- - Vanity and grooming area
- - Entry and traffic paths
- - Linen storage/closet areas
- - Water-resistant (not waterproof) surfaces OK
- - Where you'll place rugs and bath mats
When possible, separate wet and dry zones with a physical barrier or change in floor level. This prevents water from traveling to areas where it can cause damage and makes the bathroom easier to keep dry after showering.
Pro Tips from Bathroom Designers
Draw multiple layout options
Create 3-4 different arrangements before settling on one. What seems obvious at first might not be the best solution once you see alternatives on paper.
Think about the daily routine
Walk through a typical morning: enter bathroom, use toilet, shower, dry off, groom at vanity. Does the layout flow naturally, or are you zigzagging around fixtures?
Plan for storage early
Storage needs affect fixture selection. A larger vanity with drawers might be worth sacrificing shower size. Recessed medicine cabinets need wall depth.
Consider sight lines from the door
What do you see when the bathroom door opens? Ideally not the toilet. Position the vanity or shower as the first view when entering.
Account for fixture connections
Leave access space for shutoff valves, P-trap cleanouts, and toilet supply lines. You'll need this access for maintenance.
Measure twice, then measure again
The cost of re-measuring is zero. The cost of ordering a vanity that's 2 inches too wide for the space is hundreds of dollars and weeks of delay.
Common Floor Plan Mistakes to Avoid
Not measuring existing plumbing locations
Why it's a problem: Leads to budget-busting surprises when you realize the toilet drain needs to move 3 feet
What to do instead: Locate and precisely measure every drain and supply line before starting your layout
Forgetting about door swing clearance
Why it's a problem: Results in doors that hit toilets, vanities, or can't fully open
What to do instead: Draw the full 90-degree swing arc for every door and verify it clears all fixtures
Using advertised fixture dimensions
Why it's a problem: Marketing dimensions don't include handles, trim, or installation clearances
What to do instead: Use actual installation dimensions from spec sheets, add 1-2 inches for handles
Planning only for fixtures, not storage
Why it's a problem: Ends up with no room for towels, toiletries, cleaning supplies
What to do instead: Plan storage locations (medicine cabinet, linen closet, vanity drawers) during layout phase
Ignoring code clearance minimums
Why it's a problem: Results in failed inspections, expensive rework, or uncomfortable daily use
What to do instead: Verify every clearance against local code requirements before finalizing layout
Floor Plan Tools and Software
While graph paper works perfectly well, digital tools can speed up the process and make it easier to try multiple layouts. Here are your options:
Free Options
- Floorplanner.com - Easy drag-and-drop, good fixture library
- RoomSketcher - Free basic plan, 3D views available
- SketchUp Free - Powerful but steeper learning curve
- MagicPlan app - Uses phone camera to measure
Paid/Pro Options
- SmartDraw - Templates for bathroom layouts, $10/mo
- Home Designer Suite - Full 3D, ~$100 one-time
- Chief Architect - Professional-grade, $200+
- Professional designer - $200-500 for bathroom plan
Frequently Asked Questions
What is the minimum clearance required in front of a toilet?
Building codes require a minimum of 21 inches of clear space in front of a toilet, measured from the front of the bowl to any wall or obstruction. However, 24-30 inches is more comfortable for daily use. The toilet center must also be at least 15 inches from any side wall or obstruction.
Can I move my toilet to a different location in the bathroom?
Yes, but it's expensive and complicated. Toilets require a 3-4 inch drain pipe that must maintain proper slope (1/4 inch per foot) to the main stack. Moving a toilet more than a few inches often means opening the floor and rerouting the drain, which can cost $1,000-3,000 or more. If possible, design your layout to keep the toilet near its current location.
What's the minimum shower size allowed by code?
Most building codes require a minimum interior shower dimension of 30x30 inches, though 32x32 inches is more common as the practical minimum. For comfortable use, aim for at least 36x36 inches for a square shower, or 36x48 inches for a rectangular one. Walk-in showers typically start at 36x60 inches.
How do I account for door swing in my bathroom floor plan?
Draw an arc showing the full swing path of the door (usually 90 degrees). The door must not hit the toilet, vanity, or any fixture when opened. If space is tight, consider a pocket door (slides into wall), barn door (slides along wall), or an outward-swinging door. Never have a door swing into a toilet or shower.
What's the difference between wet and dry zones in bathroom design?
Wet zones include the shower, tub, and immediate splash areas that will regularly get water on surfaces. Dry zones are areas that should stay dry, like the toilet area and vanity zone. Good bathroom design separates these zones to prevent water damage, improve ventilation, and allow for different flooring or finish treatments in each area.
Ready for the Next Step?
With your floor plan complete, you now have a clear picture of your bathroom layout. Next, plan your shower and tub configuration to finalize the wet zone details.