What is a tile calculator?
A tile calculator estimates how many tiles you need to cover a floor or wall. By entering the room dimensions and tile size, it calculates the total area and the number of tiles required, including an allowance for cuts and waste. This prevents under-ordering and avoids costly mid-project trips to the store.
How do you calculate the number of tiles needed?
The tile count is calculated using these formulas:
Room area = room length × room width
Tile area = (tile length ÷ 100) × (tile width ÷ 100)
Tiles needed = ⌈ room area × (1 + waste % ÷ 100) ÷ tile area ⌉ (rounded up)
Room dimensions are entered in metres; tile dimensions in centimetres. The waste factor accounts for cuts, breakage, and future repairs.
Grout joints between tiles mean each tile occupies slightly more floor or wall space than its face size. Use the grout gap field to enter the joint width in millimetres — a typical value is 2–3 mm. The calculator automatically adjusts the effective tile size, so you do not need to modify tile dimensions manually.
What waste factor should I use for tiles?
A 10% waste factor is standard for straight, grid-pattern layouts. Use 15% for rooms with many corners, alcoves, or irregular shapes. For diagonal or herringbone patterns, use 15–20% because cutting at an angle generates significantly more offcuts. If you are using natural stone tiles, add at least 10% regardless of layout due to the higher breakage rate during cutting.
What are some tile calculation examples?
Bathroom floor: 2.5 × 3 m room, 30 × 30 cm tiles, 10% waste. Room area = 7.5 m². Tile area = 0.09 m². Tiles = ⌈ 7.5 × 1.10 ÷ 0.09 ⌉ = ⌈ 91.67 ⌉ = 92 tiles.
Kitchen backsplash: 0.6 × 4 m wall, 10 × 10 cm tiles, 15% waste. Room area = 2.4 m². Tile area = 0.01 m². Tiles = ⌈ 2.4 × 1.15 ÷ 0.01 ⌉ = 276 tiles.
Living room floor: 5 × 6 m room, 60 × 60 cm tiles, 10% waste. Room area = 30 m². Tile area = 0.36 m². Tiles = ⌈ 30 × 1.10 ÷ 0.36 ⌉ = 92 tiles.
When is a tile calculator useful?
A tile calculator is essential when planning a bathroom renovation, kitchen tiling, or flooring project. Ordering too few tiles is a common mistake — tiles from a different production batch can differ slightly in shade, making top-ups noticeable. If your room dimensions are in feet or inches, convert them first using our area converter. For budgeting your full renovation, the paint calculator helps estimate wall paint quantities alongside tile quantities. Enter a price per tile to get an instant cost estimate for your project — useful when comparing tile options at different price points.
How many extra tiles should I buy?
Always buy at least 10% more tiles than your calculated need. Store a few spare tiles after installation — if a tile cracks years later, you will need an exact match. Production dye lots vary between batches, so tiles purchased later may not match. For large-format tiles (60 cm and above), consider ordering 15% extra because cutting errors have a higher material cost per mistake.
What tile size is best for small rooms?
Larger tiles (e.g. 60 × 60 cm) can make a small room feel bigger because fewer grout lines create a more continuous surface. However, very large tiles require a perfectly flat subfloor and professional installation. For bathrooms under 5 m², 30 × 30 cm or 30 × 60 cm tiles are a practical choice — they are easier to cut around fixtures and require fewer adjustments. Mosaic tiles (under 10 cm) are popular for shower walls but generate more grout lines and require more cutting waste, so use a 20% waste factor. Use our percentage calculator to quickly scale up your tile budget if prices change.