Tile for a Bathroom Floor
Free calculator with pre-filled dimensions • Updated March 2026
A standard 8×5 bathroom floor needs about 44 tiles (12×12") — roughly 5 boxes with 10% waste factor.
Open calculator with these dimensions →Tiling a Bathroom Floor: Complete Guide
Bathroom floor tile is a high-impact renovation that costs $200–$500 in materials for a standard 5×8 bathroom but adds significant value and waterproofing. A 40 sq ft bathroom floor with 10% waste needs about 44 tiles in the common 12×12-inch size.
Material Breakdown
| Material | Quantity | Cost (2026) |
|---|---|---|
| Porcelain tile (12×12") | 44 tiles (5 boxes) | $80–$250 |
| Thin-set mortar | 1 bag (50 lb) | $15–$25 |
| Grout (sanded) | 10 lbs | $12–$18 |
| Cement backer board | 3 sheets (3×5') | $30–$45 |
| Tile spacers | 1 bag (1/8") | $4–$6 |
Total: $140–$345 for materials. Professional installation: $500–$1,200.
Why 10% Waste Factor?
Bathroom floors have toilets, vanities, and door frames that require cutting tiles. Straight-lay patterns waste about 10%. Diagonal patterns waste 15%. Herringbone or complex patterns can waste 20% or more. Always round up to the next full box.
Pro Tips
- Always use porcelain, not ceramic, in bathrooms. Porcelain absorbs less than 0.5% water vs. 3–7% for ceramic. This matters in a room that's regularly wet.
- Choose textured or matte finish. Glossy smooth tile is dangerously slippery when wet. Look for tiles rated with a coefficient of friction (COF) of 0.42 or higher for wet areas.
- Install cement backer board over plywood. Never tile directly on plywood in a bathroom — it flexes and swells. HardieBacker or Durock cement board provides a stable, waterproof substrate.
Frequently Asked Questions
How many tiles for a bathroom floor?
A standard 8×5 bathroom (40 sq ft) needs about 44 tiles in 12×12-inch size with 10% waste. Smaller tiles like 6×6 require about 176 tiles. Larger 24×24 tiles need only 12 tiles.
How much does it cost to tile a bathroom floor?
DIY materials cost $140–$345 for a standard bathroom. Professional installation runs $500–$1,200 in 2026, depending on tile choice and pattern complexity.
Can I tile over existing bathroom tile?
Yes, if the existing tile is firmly bonded, level, and in good condition. Clean thoroughly, apply a bonding primer, and use modified thin-set. However, this raises the floor height by 3/8 inch, which may affect door clearance and toilet flange height.