How Many Tiles Do I Need for a Bathroom Floor? (With Size Charts)

Short answer: A standard 5x8 bathroom with a tub has about 27.5 square feet of floor to tile. With a straight layout and 10% extra, you'll need about 30 tiles in 12x12, 16 tiles in 12x24, or 117 tiles in 6x6.

The exact number depends on your room's shape, your tile size, and the pattern you choose. Here's how to work it out for your bathroom, plus charts for the most common sizes.

Step 1: Measure Only the Floor You'll Tile

Measure the length and width of the floor in feet and multiply them. Then subtract anything that sits on the floor permanently and won't get tile underneath:

• Bathtub or shower base: a standard alcove tub is about 5 ft × 2.5 ft = 12.5 sq ft
• Built-in vanity cabinet: usually not tiled underneath (freestanding or wall-hung vanities are)

You do tile under the toilet, so don't subtract it.

Example: a 5 × 8 bathroom is 40 sq ft. Subtract the tub (12.5 sq ft) and you're left with 27.5 sq ft of floor to tile.

Step 2: Divide by the Tile Size

Each tile covers a fixed area (plus a sliver of grout line). Common sizes:

For 27.5 sq ft of 12x12 tile, that's about 27 tiles before waste. (Grout lines make each tile "cover" slightly more than its own size, which is why it isn't exactly 27.5.)

Step 3: Add Extra for Cuts and Breakage

This is the step people skip, and it's the reason they end up back at the store. Every row ends with a cut tile, some tiles crack, and you'll want spares for future repairs.

So 27 tiles × 1.10 = 30 tiles for a straight layout. The same floor in a diagonal pattern needs 32 tiles, and 12x24 tiles in herringbone need 17.

Tile Count Charts for Common Bathroom Sizes

All counts below assume 1/8" grout lines, a straight layout, and 10% extra, the same method our tile calculator uses. Areas are the full room; subtract your tub or vanity first if needed.

Tile is usually sold by the box or by the square foot, so convert your count to boxes and round up. A box label will say how many square feet it covers.

Which Tile Size Is Best for a Small Bathroom?

Bigger isn't always better on a bathroom floor:

• 12x24 and 24x24 tiles make a small floor look larger and have fewer grout lines to clean, but they need a very flat subfloor and are harder to slope toward a floor drain.
• 12x12 tiles are the easy middle ground: forgiving to install and simple to cut around a toilet.
• Small tiles and mosaics (2" hexagons, penny tile) grip better underfoot when wet and handle slopes well, which is why they're popular in shower floors. They also use far more grout.

Laying It Out Before You Commit

Before mixing any thinset, dry-lay a row of tiles with spacers from the center of the room toward each wall. You want to avoid a thin sliver of tile (less than half a tile wide) at the doorway, where it's most visible. If you get one, shift your starting line by half a tile.

What Else You'll Need

Tile is only part of the shopping list. For a bathroom floor you'll also need thinset mortar, grout, spacers, and a way to cut tile cleanly:

For grout, the amount depends on tile size and joint width rather than just floor area. Our grout calculator works it out in pounds and bags.

The Bottom Line

For a typical 5x8 bathroom with a tub (27.5 sq ft of floor):

• 12x12 tile: about 30 tiles
• 12x24 tile: about 16 tiles
• 6x6 tile: about 117 tiles
• Add 15–20% instead of 10% for diagonal or herringbone layouts

Every bathroom is a little different, so plug your own measurements into the free tile calculator for an exact count, waste included.