Bathroom Tile Calculator
Estimate floor tile for a bathroom, with extra allowance for the many cuts around fixtures.
Calculator
Free, runs entirely in your browser, and your numbers never leave your device. Results are estimates for planning only.
What this calculator does
Bathroom floors are small but full of cuts — around the toilet, vanity, and tub — so they waste proportionally more tile than a big open room. This tool estimates the boxes for a bathroom floor with a slightly higher allowance for those fiddly cuts.
How to use it
- Enter the bathroom's length and width.
- Enter the coverage per box for your tile (small-format tile boxes cover less).
- Keep the waste a little higher (about 12–15%) for cuts around fixtures, then read the boxes.
The formula
Area = length × width. Order area = area × (1 + waste%). Boxes = ⌈order area ÷ pack coverage⌉.
Example calculation
A 5 ft × 8 ft bathroom floor, tile boxes covering 12 sq ft, 12% waste:
- Floor area: 5 × 8 = 40 sq ft
- With 12% waste: 40 × 1.12 = 44.8 sq ft
- Boxes: ⌈44.8 ÷ 12⌉ = 4 boxes
Result: 4 boxes — small floors round up quickly, so the spare tile is built in.
Buying and planning tips
- Bump the waste to 12–15% for the cuts around the toilet flange, vanity, and tub.
- Dry-lay tiles to avoid a thin sliver against the most visible wall.
- Buy a little extra; bathroom tile is a common future repair after a leak.
Common mistakes to avoid
- Using a 10% allowance when a fixture-filled bathroom needs more.
- Forgetting the area hidden under the vanity that may still need tile.
- Ordering exactly to area, then coming up short on the last few cut pieces.
Assumptions and limits
- A slightly higher waste allowance reflects the many cuts in a small, fixture-filled room.
- Coverage per box is taken from your input; small-format boxes cover less area.
- The floor is treated as a rectangle; subtract a built-in only if it won't be tiled under.
Frequently asked questions
How much tile do I need for a bathroom floor?
Find the area, add about 12–15% for the cuts around fixtures, divide by the coverage per box, and round up. A small 5×8 ft bathroom needs roughly 4 boxes.
Why does a small bathroom need more waste?
There are many cuts around the toilet, vanity, and tub relative to the floor size, so a higher percentage of tile becomes offcuts.
Should I tile under the vanity?
It is optional. Tiling under a freestanding vanity makes future changes easier; if you won't, subtract that area from what you enter.
How much spare tile should I keep?
Keep several tiles from the same lot. Bathroom floors often need a repair after a plumbing fix, and matching later is hard.
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