How Many Tiles for a Bathroom Floor?
Quick Answer
A typical 5×8 foot bathroom floor is 40 square feet. Using 12×12 inch tiles (1 sq ft each), you need 40 tiles, or about 44 after a 10% waste factor for cuts around fixtures.
- 5×8 bathroom (40 sq ft): ~44 12×12 tiles
- 12×12 tile = 1 sq ft each
- 12×24 tile = 2 sq ft each (half the count)
- Add 10–15% waste for cuts around toilet and vanity
Formula
Divide the floor area by the coverage of one tile, then add 10 to 15% for waste. A 12×12 tile covers 1 sq ft; a 12×24 tile covers 2 sq ft.
Step-by-Step Calculation
- 1
Floor area
5 × 8 = 40 square feet
- 2
Tiles at 1 sq ft each
40 ÷ 1 = 40 tiles
- 3
Add 10% waste
40 × 1.10 = 44 tiles
- 4
For 12×24 tiles
40 ÷ 2 = 20 → 22 tiles with waste
Bathroom Floor Tiles by Size
| Bathroom Size | Floor Area | 12×12 Tiles | 12×24 Tiles |
|---|---|---|---|
| 5×7 (half bath) | 35 sq ft | 39 | 20 |
| 5×8 | 40 sq ft | 44 | 22 |
| 8×10 | 80 sq ft | 88 | 44 |
| 10×12 (master) | 120 sq ft | 132 | 66 |
Counts include a 10% waste factor. Diagonal or herringbone patterns need 15–20% waste due to more cut tiles.
Pro Tips
- Bathroom floors require a waterproof membrane (Schluter Ditra or liquid membrane like RedGard) under the tiles — this adds $1.50–$3.00/sq ft to your material cost but prevents the most expensive bathroom failure: water leaking through tile joints into the subfloor.
- Use smaller tiles (2×2 or hexagonal mosaic sheets) in the shower floor area — they conform better to the required 1/4-inch-per-foot slope toward the drain. Standard 12×12 tiles will not follow a shower floor slope without lippage issues.
- For a typical 5×8 bathroom (40 sq ft), you will make about 20–25 cuts. Rent a wet tile saw ($40–$60/day) rather than attempting these cuts with a snap cutter — bathroom floors have toilets, vanities, and doorways that require precise curved and notch cuts.
- Lay out your tile pattern starting from the center of the doorway, not the center of the room. The first tile you see when entering should be a full tile — cut tiles should be at the edges behind the toilet and under the vanity where they are less visible.
Key Cost Factors
- A 5×8 bathroom floor (40 sq ft) in ceramic tile costs $60–$200 in tile materials (44 tiles at $1.50–$5.00 each). Add $30–$50 for thinset, grout, and sealant. Waterproof membrane adds $60–$120. Total DIY materials: $150–$370.
- Professional bathroom tile installation runs $8–$15 per square foot ($320–$600 for 40 sq ft). The premium over general tile work reflects the waterproofing, slope requirements, and tight working conditions in bathrooms. Many homeowners DIY their floors but hire a pro for shower tile — the stakes for waterproofing errors are too high.
Common Mistakes to Avoid
- Ordering no extra for cuts. Bathrooms are full of cuts around toilets, vanities, and tight walls, wasting 15–20%. Ordering exactly the floor area guarantees a shortage.
- Ignoring the dye lot. Buying a couple more boxes later rarely matches shade. Order all boxes at once with the same lot number.
- Using wall tile on the floor. Wall tiles are often not rated for foot traffic or slip resistance. Use floor-rated tile with an appropriate slip rating in a bathroom.
- Skipping waterproofing. Tiling a bathroom floor without a proper waterproof membrane or backer board leads to leaks and rot beneath the tile.
Related Project Considerations
- Prioritize slip resistance. Choose a floor tile with a suitable coefficient of friction; polished tile gets dangerous when wet in a bathroom.
- Plan the layout around fixtures. Center the pattern and avoid thin slivers at the most visible wall; dry-lay first to fine-tune cuts around the toilet and vanity.
- Waterproof the substrate. Use cement backer board and a waterproofing membrane, especially near the tub and shower, before setting any tile.
Frequently Asked Questions
How much waste should I add for bathroom tile?
Add 10% for a standard straight (grid) layout, and 15 to 20% for diagonal, herringbone, or brick-lay patterns that require more angle cuts. Bathrooms with many fixtures (toilet flange, vanity base, shower curb) also generate more cuts and waste. Buying extra from the same production batch also protects against future repairs — matching a discontinued tile years later is nearly impossible.
What size tile is best for a small bathroom?
Larger tiles like 12×24 make a small bathroom feel bigger because fewer grout lines create a cleaner, more open visual. Fewer grout lines also mean less maintenance and easier cleaning. Very small mosaic tiles (1×1 or 2×2) are ideal on shower floors where you need more grout lines for grip and better slope conformity to the drain, but they require significantly more labor to install.
How much does it cost to tile a bathroom floor?
Tile materials run $1–$15 per square foot depending on type (ceramic, porcelain, or natural stone). For a typical 40 sq ft bathroom floor, expect $150–$500 in tile plus $30–$60 for thin-set, grout, and spacers. Professional installation adds $5–$10 per square foot, or $200–$400 for the labor. Waterproofing membrane and backer board, if needed, add another $2–$4 per sq ft.