Work out how many tiles to buy. This free tile quantity calculator turns your area and tile size into tiles needed, adds a waste allowance for cuts, and gives the number of boxes.
Enter the area (room size or total) and your tile dimensions. A waste allowance of about 10% covers cuts and breakages — use 15% for diagonal or patterned layouts.
Tiles needed = area ÷ tile area, rounded up, plus a waste margin. Buy from the same batch where possible (shades vary between batches) and keep spares for future repairs.
How the Tile Quantity Calculator Works
This tool converts a room’s floor or wall area and your chosen tile size into the number of tiles to buy, adding a waste allowance for cuts and breakage before optionally converting the count into boxes.
Formula: Tile area = Tile Width × Tile Height. Raw tiles = Area ÷ Tile area. Tiles needed = ROUND UP (Raw tiles × (1 + Waste% ÷ 100)). Boxes needed = ROUND UP (Tiles needed ÷ Tiles per box).
- Room Length & Width — used in “Room size” mode to calculate area automatically
- Total area — entered directly in “Total area” mode if you already know the square footage/metreage
- Tile Width & Height — the individual tile’s dimensions, in cm or inches
- Waste % — extra tiles to cover cuts and breakage (10% default, 15% suggested for diagonal or patterned layouts)
- Tiles per box (optional) — converts the final tile count into a number of boxes to purchase
Example Scenarios
| Room / Area | Tile Size | Waste % | Tiles Needed |
|---|---|---|---|
| 5m × 4m (20 m²) | 30 × 30 cm | 10% | 245 |
| 4m × 3m (12 m²) | 30 × 30 cm | 10% | 147 |
| 3m × 3m (9 m²) | 45 × 45 cm | 10% | 49 |
| 5m × 3m (15 m²) | 60 × 60 cm | 15% | 48 |
| 6 m² (direct entry) | 20 × 20 cm | 5% | 158 |
Tile Quantity Calculator FAQ
How much extra tile should I buy for waste and cuts?
10% is a typical starting point for a rectangular room laid straight. Bump it up to 15% or more for diagonal layouts, herringbone patterns, or rooms with lots of corners, alcoves, or fixtures to cut around.Should I use the tile’s nominal size or its actual measured size?
Use the tile’s actual measured dimensions where possible, since nominal sizes (like “12×12”) can differ slightly from the real manufactured size, especially with rectified or handmade tiles, and small differences add up over a large area.Does this calculator account for diagonal or herringbone layouts?
Not directly — it calculates area-based tile count, but you compensate for pattern complexity by raising the waste percentage, since diagonal and herringbone layouts create more offcuts than a straight grid layout.What if I don’t know how many tiles come in a box?
Leave the “Tiles per box” field blank and the calculator will still give you the total tile count with waste included; check your tile’s packaging or the supplier’s listing once you’ve picked a product to add the box conversion.Does grout line width change how many tiles I need?
Grout lines add a small amount to the effective footprint of each tile, but for most residential jobs this difference is minor enough that the waste percentage already absorbs it; for very large tiles or wide grout joints, consider nudging the waste % up slightly.What’s the difference between “Room size” and “Total area” input modes?
“Room size” mode multiplies the length and width you enter to get area automatically, while “Total area” mode lets you enter a pre-calculated square footage or metreage directly — useful for irregular rooms where you’ve already summed multiple sections.Related Calculators
Not sure of your room’s exact area yet? Start with the square footage calculator to nail down the dimensions first. If you’re refreshing the same room, the paint quantity calculator and wallpaper calculator can help plan the walls to match.