How to Tile a Bathroom: Materials, Cost & Calculator Guide

Measuring Your Bathroom for Tile

Measure floor and wall areas separately — they often use different tile sizes and materials. For the floor, measure length × width in feet. For walls, measure each wall's width × height and add them together, then subtract door and window openings. For a shower or tub surround, measure each wall panel individually (typically three walls: back wall and two side walls).

Example — 5×8 bathroom: Floor = 40 sq ft. Four walls at 8-foot ceiling height = (5+8+5+8) × 8 = 208 sq ft, minus door (21 sq ft) and standard window (15 sq ft) = 172 sq ft of wall tile. Always measure each zone separately and add waste factor before purchasing.

Choosing the Right Tile Size

Tile size dramatically affects the look and feel of a bathroom:

12×12 or 12×24 inch tiles: Popular for bathroom floors. Fewer grout joints mean easier cleaning. Large format tiles make small rooms appear bigger.
3×6 subway tile: The classic choice for shower walls and backsplashes. Timeless, inexpensive ($1–4/sqft), and widely available.
4×4 or 4×6 ceramic: Traditional bathroom wall tile. Affordable and easy to install.
Mosaic tile (1×1, 2×2): Used for shower floors where slip resistance matters. More grout lines mean more grip.

Waste Factor: How Much Extra to Buy

Always buy more tile than your measurements suggest. Cuts, breakage, and future repairs require extra material:

Standard grid pattern: Add 10% waste
Diagonal (45°) pattern: Add 15–20% waste — diagonal cuts create more unusable pieces
Herringbone or complex patterns: Add 15–20% waste

Buying from the same dye lot is critical — tile color varies slightly between production runs. Always purchase all your tile at once.

Backer Board Requirements

Regular drywall cannot be used as a substrate for bathroom tile in wet areas. You need cement backer board (such as HardieBacker or Durock) or a waterproof foam board (such as Schluter KERDI-BOARD). Backer board is required on all shower walls, tub surrounds, and bathroom floors. Calculate square footage the same way as tile and add 10% waste.

Grout, Mortar & Adhesive

Tile mortar (thinset): One 50-lb bag covers approximately 40–50 sq ft. Buy one bag per 40 sq ft of tile.
Grout: Approximately 1 lb of grout per sq ft for standard 1/8 inch joints with 12×12 tile. Narrow joints need less; wide joints need more.
Grout types: Sanded grout for joints wider than 1/8 inch; unsanded for narrower joints. Epoxy grout is most stain-resistant for shower floors.

Tile Installation Costs

Material costs range from $2–$15 per sq ft for tile itself. Basic ceramic is $2–4/sqft; porcelain runs $3–8; natural stone $5–15 or more. Professional installation labor typically runs $8–$15 per sq ft including setting, grouting, and sealing. A full 5×8 bathroom tile job (floor + walls) typically costs $1,500–$4,000 in labor, plus $300–$1,000 in materials depending on tile selection.

Frequently Asked Questions

How much tile do I need for a 5x8 bathroom floor?

A 5×8 foot bathroom floor = 40 sq ft. Add 10% waste = 44 sq ft. If using 12×12 tiles, you need 44 tiles minimum (each covers 1 sq ft). If using 12×24 tiles, you need 22 tiles. Always round up to the nearest full box and buy from the same dye lot.

What size tile is best for a small bathroom?

Contrary to old advice, larger tiles (12×24 or even 24×24) can make a small bathroom feel bigger by creating fewer grout lines and a more continuous floor plane. However, tiles larger than 12×12 require a very flat subfloor and more precise installation. 12×12 or 12×24 is the sweet spot for most small bathrooms.

Do I need backer board under bathroom tile?

Yes, in all wet areas. Standard drywall absorbs moisture and will eventually crumble behind tile in showers and tub surrounds. Use cement backer board or a waterproof foam backer board on all shower walls and bathroom floors. In a dry bathroom floor area (no direct water exposure), some installers use exterior-grade plywood, but cement board is always the safer choice.

How much does bathroom tile installation cost?

Expect to pay $8–$15 per sq ft for professional tile installation, including labor, mortar, and grout. For a 5×8 bathroom with floor and three shower walls, total square footage might be 120–160 sq ft, putting labor at $960–$2,400. Add tile material costs ($2–$15/sqft) for a total project range of roughly $1,500–$5,000 depending on tile choice.

What's the best grout for shower walls?

Epoxy grout is the most durable and stain-resistant option for showers — it's non-porous and doesn't require sealing. However, it's more expensive ($30–$50/bag vs. $10–$20 for cement grout) and harder to work with. A quality sanded or unsanded cement grout sealed after installation works well for most shower walls. Re-seal cement grout annually to maintain water resistance.