8x10 Room Tile Calculator
80 sq ft — master bathroom or utility room.
Open Tool →How Many Tiles Do I Need for a 5x8 Bathroom?
5x8 is 40 sq ft, a compact bathroom footprint where the toilet, vanity and tub edge control the tile layout more than the open floor does.
Instant answer: A 5x8 bathroom covers 40 sq ft. With 15% waste, plan on about 46 sq ft of tile or roughly 104 8x8 tiles, 46 12x12 tiles, or 414 4x4 tiles.
What are you tiling?
Room size
This calculator is pre-filled for a 5 ft × 8 ft (40 sq ft) room. Change the numbers below if your room is a different size.
Tile size (inches)
Common sizes for this room (click to fill):
15%
15% default (toilet base, vanity, tub cutouts) · 20% around a shower pan · 10% only if the floor is completely open
Tiles to Buy (incl. wastage)
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Tiles Without Wastage
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Area (sq ft)
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Area (m²)
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Planning Tile for a Small Bathroom
A 5×8 foot bathroom (40 sq ft) is the most common small bathroom size in US homes — and the most technically demanding to tile. Once you subtract the tub surround (30"×60"), vanity cabinet, and toilet footprint, the actual open floor is just 15–18 sq ft. Nearly every single tile will need a cut. Budget 15–20% waste, not the standard 10%.
Waterproofing Checklist
Grout is not waterproof. Even high-quality sanded grout is porous enough to let moisture reach the subfloor over time. Complete these steps before laying a single tile:
- ✅ Install cement board or Hardiebacker over the subfloor — never tile over bare plywood in a wet room.
- ✅ Apply a liquid waterproof membrane (Redgard, Mapei Aquadefense, or Schluter Kerdi-Band at seams) over the entire floor, not just the shower area. Bathroom floors get wet from splashing, steam, and leaks.
- ✅ Let the membrane cure fully — typically 24 hours — before tiling. Rushing this step is the #1 cause of long-term subfloor rot.
- ✅ Fill the toilet flange gap with silicone, not grout. Grout around the flange cracks and allows water to wick under the floor.
Working Around the Toilet & Vanity
The toilet and vanity are the two features that drive up your waste percentage the most. Here is how professionals handle them:
- Toilet Flange: Always tile the full floor before setting the toilet. The flange bolts to the floor on top of the tile. Use an angle grinder with a diamond blade to cut a smooth curve around the drain pipe — the toilet base will cover rough edges, but avoid square notch cuts which create stress fracture points.
- Vanity Cabinet: Do not tile under a fixed vanity cabinet. Tile up to the toe kick. This saves tiles and prevents hollow spots that crack underfoot. If you plan to change vanities in the future, tile underneath first.
- Shower Pan Threshold: Use a marble or metal threshold saddle at the shower entry rather than trying to cut your floor tiles to meet the shower pan drain slope at an angle.
Tile Size vs. Slip Resistance
| Tile Size | DCOF Rating | Slip Risk | Best Use |
|---|---|---|---|
| 2×2 Mosaic | 0.60+ | Very Low | Shower floors — maximum grip, mandatory on slopes |
| 4×4 Ceramic | 0.50+ | Low | Traditional bathroom floors, vintage look |
| 8×8 Matte Porcelain | 0.45+ | Low | Best all-round small bathroom tile |
| 12×12 Matte Porcelain | 0.42+ | Medium-Low | Good for 5×8 open floor area |
| 12×24 Polished Porcelain | Below 0.42 | High | Not recommended for wet bathroom floors |
Bathroom Tile Recommendations
| Tile Size (in) | Est. Quantity (15% Waste) | Why It Works in a 5×8 |
|---|---|---|
| 8×8 Matte Porcelain | 104 pieces | Balanced grout lines, high slip resistance, easy to cut around fixtures |
| 12×12 Matte Porcelain | 46 pieces | Fewer grout lines to clean, works if subfloor is flat |
| 12×24 Rectified | 23 pieces | Makes room feel wider when run along the 8-ft wall — needs perfect substrate |
| 2×2 Mosaic Sheet | ~5 sheets | Mandatory inside the shower pan; conforms to slope without cutting |
Common Bathroom Tiling Mistakes
- Starting at the wall. Never begin laying from a wall. Find the center of the open floor area and work outward. This ensures the smallest cuts are hidden at the perimeter, not in the middle of the doorway.
- Skipping back-buttering. In wet zones, you need 95% mortar coverage. For 12×12+ tiles, use a 1/4"×3/8" notch trowel and back-butter every tile to eliminate hollow spots where water can collect.
- Using wall grout on floors. Non-sanded grout (used on walls) is too weak for floor joints. Use polymer-modified sanded grout on any joint over 1/8" wide.
- Forgetting the shower floor vs. bathroom floor. The shower floor requires a sloped mortar bed and mosaic tile. It is a separate installation from the bathroom floor tile — treat it as such.
5×8 Bathroom Tile FAQs
Yes. Always tile the full floor before setting the toilet. The toilet flange sits on top of the tile, and leaving a gap around it creates an uneven base that can crack the porcelain and cause leaks over time. The toilet base covers any rough edges around the flange cutout.
Look for tiles with a DCOF (Dynamic Coefficient of Friction) rating of 0.42 or higher for wet areas. Matte-finish porcelain and textured ceramic tiles provide significantly better grip than polished or glazed surfaces. Avoid any polished tile on bathroom or shower floors — the risk of slipping when wet is high.
Yes — the entire floor, not just the shower area. Grout is porous, and bathroom floors get wet regularly from splashing, steam, and spills. Apply a liquid waterproofing membrane (such as Redgard or Mapei Aquadefense) over your cement board before tiling. Pay extra attention to sealing the corners where the floor meets the wall.