How many tiles do I need for a 5x8 bathroom floor?
Check it with your own numbers
Open the Tile Calculator with these values
| Area length | 8 ft |
| Area width | 5 ft |
| Tile length | 12 in |
| Tile width | 12 in |
| Grout gap | 0.125 in |
| Waste | 10 % |
| Tiles per box | 10 |
| Tiles needed | 44 |
| Boxes | 5 |
| Area | 40 ft² |
The count
A 5x8 bathroom floor is 40 ft². A 12-inch tile with a 1/8-inch grout joint covers just over 1 ft². Add 10% for cuts and you need 44 tiles. At 10 tiles per box, that is 5 boxes.
What about the tub?
A standard 5x8 bath has a 60x30 inch tub across one end. Tile does not go under the tub, so the real floor is closer to 5 × 5.5 ft, about 27.5 ft². Change the length to 5.5 in the calculator and the tile count drops accordingly. Do not subtract for the toilet or vanity unless the vanity is built in; tile usually runs under a freestanding vanity.
Why 10% waste is the floor, not the ceiling
- Small rooms waste more. Nearly every tile along the walls is a cut. In a 5 ft wide room, that is a big share of the floor.
- Diagonal layout. Set on a 45, plan 15% waste.
- Large format. 12x24 tiles need more waste in a tight bath since each mistake costs two square feet.
Keep spares
Buy one extra box and store it. Tile lots change color slightly, and a cracked tile five years from now is impossible to match without one.
Small tile, small bathroom
Many people tile a 5x8 bathroom in 2-inch hex or penny tile sold in 12x12 sheets. Use the sheet size (12x12) in the calculator with a near-zero gap, since grout lines are already built into the sheet.
Underlayment
For 40 ft², one sheet of 3x5 cement board plus a partial covers the floor; uncoupling membrane comes in rolls that cover 54 ft² or more. Plan one 50 lb bag of modified thinset per 40 to 50 ft² with a 1/4 x 3/8 notch trowel.
For other sizes, use the full Tile Calculator or browse all answers.