Tile Calculator
Estimate tile count and extra material for waste.
How to use this tile calculator
- Measure the tiled area
Enter the Area length and Area width in meters for the surface to be tiled.
- Enter tile dimensions
Enter the Tile length and Tile width in centimeters (e.g. 30 × 30 for standard square tiles).
- Set the waste allowance
Enter a Waste allowance percentage — typically 10% for floors, 10–15% for backsplashes with many cuts.
- Read the tile count
The calculator shows Area, Single tile area, Tiles needed, and Tiles with waste.
- Convert to boxes
Divide tiles with waste by the number of tiles per box and round up to whole boxes.
How this tile calculator works
This tile calculator divides the total surface area by the area of a single tile to determine the base tile count, then applies a waste percentage to cover cuts, breakage, and pattern losses. It is designed for floor tile, wall tile, backsplash, and shower surround projects where you need to know how many individual tiles (or boxes of tiles) to purchase. The calculator uses centimeter-level tile dimensions for precision, since even small differences in tile size change the count significantly on large areas.
Base tiles = (area length × area width) / ((tile length ÷ 100) × (tile width ÷ 100))
Tiles with waste = ⌈Base tiles × (1 + waste% / 100)⌉ A bathroom floor measuring 3 m × 2.5 m has an area of 7.5 m². Using 30 cm × 30 cm tiles (0.09 m² each), the raw base tile count is 7.5 / 0.09 ≈ 83.33 tiles. With a 10% waste allowance, the order quantity becomes 83.33 × 1.10 ≈ 91.67, rounded up to 92 tiles. If tiles are sold in boxes of 11, you would purchase ⌈92 / 11⌉ = 9 boxes (99 tiles total), giving a comfortable buffer for breakage and future repairs.
A bathroom floor 3 m × 2.5 m has an area of 7.5 m². Using 30 cm × 30 cm tiles (0.09 m² each) with 10 % waste allowance, order 92 tiles. If sold in boxes of 11, purchase ⌈92 ÷ 11⌉ = 9 boxes.
For backsplashes with many outlet and switch cuts, use a 15% waste allowance even for small areas. The calculator's 10 % default suits most floors; increase to 15% when edge cuts and obstacles dominate the layout.
- ✓ Grout joint width is not included in the tile area; for large-format tiles with wide grout lines, the actual count may be slightly lower.
- ✓ The area is treated as a simple rectangle; complex shapes like shower niches or diagonal layouts should use a higher waste percentage.
- ✓ Tiles are assumed to be uniform in size; handmade or irregular tiles may require additional material for alignment adjustments.
- ✓ The result is rounded up because suppliers sell whole tiles, and partial tiles from cuts cannot be avoided.
- Diagonal (45°) layouts typically waste 12–15% more material than straight grid layouts because every edge tile must be cut at an angle.
- Order all tiles from the same production lot to avoid shade variation — this is a common reason to buy the full quantity upfront rather than in batches.
- For wall tiles, measure each wall face separately and add the areas together, remembering to subtract large openings like windows or shower doors.
- Keep 2–4 spare tiles after installation for future crack or chip replacements; matching tiles can be discontinued by manufacturers.
- Tile Council of North America (TCNA) Handbook for Ceramic, Glass, and Stone Tile Installation
- National Tile Contractors Association (NTCA) — material estimation and waste factor guidelines
Tile material estimation and waste factors
Tile estimation divides the total surface area by the area of a single tile to get the base count. Tile dimensions are usually given in centimeters, so a 30 cm × 30 cm tile covers 0.09 m². The calculator converts to square meters internally. Waste is essential: every edge tile must be cut to fit, and some tiles break during handling or cutting. Straight grid layouts waste less than diagonal or herringbone patterns, where almost every perimeter tile is cut at an angle. Backsplashes have many cuts around outlets, switches, and edges, so 10–15% waste is typical even for small areas. The result is rounded up to whole tiles because suppliers sell by the piece and partial tiles from cuts cannot be reused elsewhere. Ordering from a single production lot avoids shade variation between batches — a common reason to buy the full quantity upfront rather than in stages.
Common tile estimation mistakes
A frequent mistake is using the wrong units: tile dimensions are in centimeters, while area is in meters. Mixing these leads to wildly wrong counts. Another error is forgetting that grout lines slightly reduce the number of tiles needed for a given area — the calculator is conservative, so you may end up with a few extra tiles, which is preferable to running short. For complex layouts like shower niches or L-shaped backsplashes, measure each surface separately and add the areas before entering; using a single rectangle that encloses the whole space overestimates. Finally, buying exactly the calculated count with no spares is risky. Tiles can be discontinued, and matching replacements for future repairs may be impossible. Keep 2–4 spare tiles after installation in case of cracks or chips. Ordering full boxes is usually cheaper per tile and ensures shade consistency within the lot.
Tile calculator FAQs
Does this calculator account for grout spacing?
No. Grout lines reduce the number of tiles slightly for a given area, so the estimate is conservative. For large-format tiles with wide grout joints (5 mm+), you may need a few fewer tiles than calculated.
What waste percentage should I use for a backsplash?
Backsplashes have many cuts around outlets, switches, and edges, so 10–15% waste is recommended even for small areas.
Can I use this for mosaic sheets?
You can use the area calculation, but mosaic sheets have their own coverage ratings per sheet. Divide the total area by the sheet coverage instead of individual tile dimensions.
Why should I round up to full boxes?
Buying full boxes is usually cheaper per tile, ensures shade consistency within the lot, and provides spare tiles for repairs.
How do I estimate tiles for a shower?
Measure each wall and the floor separately, subtract the drain area and any large openings, then add the areas together before entering them into the calculator. Use at least 10% waste for the cuts around corners and fixtures.