Bathroom Tile Layout Planner
Calculate tiles, cuts, grout, and total cost for any bathroom tile project.
Enter your room and tile dimensions to plan your layout.
How to Use This Bathroom Tile Layout Planner
Enter your room's length and width in your preferred unit (inches, feet, centimeters, or meters). Then input your tile's length and width, grout joint size, waste factor, and layout pattern. Hit "Calculate Tile Layout" to see exactly how many tiles you need, how many boxes to buy, expected cuts, grout coverage, and total cost.
For best results, measure your room to the nearest quarter inch. If your room has alcoves or irregular shapes, calculate each rectangle separately and add the results together.
Why This Matters
Buying too few tiles mid-project is a nightmare — dye lots change between production runs, meaning new tiles won't match. Buy too many and you've wasted money. A good bathroom tile layout calculator bridges that gap.
Consider a standard 8×10 foot bathroom (80 sq ft). Using 12×12 inch tiles with a ⅛" grout joint and a 10% waste buffer, you'd need about 90 tiles. But switch to a diagonal (45°) pattern and waste jumps to 15–20%, pushing you closer to 97 tiles — an entire extra box. Herringbone and offset patterns have similar implications.
Tile size matters too. Large-format 24×24 tiles in a small 5×8 bathroom mean nearly every edge tile needs a cut, driving up both labor time and tile waste. Professional installers usually recommend a tile size no more than half the room's shortest dimension for manageable layouts.
This tool gives you the numbers upfront so you walk into the tile store confident, not guessing.
How It's Calculated
All measurements are converted to inches internally for consistency. The effective tile size includes the grout joint:
Effective tile size = Tile dimension + Grout joint size
Then:
- Tiles across = ⌈ Room Width ÷ Effective tile width ⌉
- Tiles down = ⌈ Room Length ÷ Effective tile length ⌉
- Total tiles (net) = Tiles across × Tiles down
- Total tiles (with waste) = Net tiles × (1 + Waste% ÷ 100)
- Area = Room Length × Room Width (converted to sq ft)
- Diagonal pattern adds ~15% extra waste on top of your selected waste factor because corner cuts are larger and more numerous.
- Herringbone adds ~20% extra waste due to angled interlocking cuts.
For grout: Grout coverage estimates ~1 lb per 50 sq ft for ⅛" joints with 12×12 tiles, scaling proportionally with joint width and tile surface area ratio.
Tips & Common Mistakes
- Always add at least 10% waste — even pro installers break tiles. For diagonal/herringbone patterns, use 15–20%.
- Check dye lot numbers when buying multiple boxes. Order all tiles at once so they come from the same production batch.
- Plan your starting point — centering the layout on the most visible wall prevents awkward slivers at doorways. A sliver less than ½ a tile width looks unprofessional.
- Measure twice, order once — add 5–10% for future repairs. Discontinued tiles are nearly impossible to match years later.
- Grout joint size affects appearance significantly — ⅛" joints look modern and clean; ¼"+ joints show more variation and are easier to achieve with floor tiles that have slight size tolerances.
Frequently Asked Questions
How much waste should I add for a bathroom tile project?
For a straight grid pattern, 10% is standard. For offset/brick patterns, use 10–12%. For diagonal (45°) or herringbone patterns, plan for 15–20% waste because the angled cuts at walls and corners produce more unusable offcuts. If your bathroom has many corners, niches, or obstacles like a toilet base, add another 5%.
What's the best tile size for a small bathroom?
For a 5×8 bathroom, 12×12 inch tiles are a popular choice — large enough to look modern, small enough to keep cuts manageable. Large-format tiles (24×24 or bigger) can make a small bathroom feel more spacious but require a very flat subfloor and produce significant edge waste. Mosaic tiles (2×2 or smaller on mesh sheets) work great for shower floors because they conform to the slope toward the drain.
How do I calculate how many boxes to buy?
Find the tiles per box on the product packaging (often listed with the coverage in sq ft). This calculator does it for you — just enter tiles per box and it'll show you the exact number of boxes rounded up to the nearest whole box. Never round down; buying a partial replacement box later almost never works due to dye lot differences.
Does grout joint size affect how many tiles I need?
Yes, but the effect is small for typical joint sizes. A ⅛" grout joint on a 12×12 tile means each tile effectively takes up 12.125×12.125 inches. Across a 10-foot span, this reduces the tile count by less than one tile — but it does shift where your edge cuts fall. Larger joints (¼" or more) can noticeably change cut positions, especially in smaller rooms.