Home & DIY
How many tiles do you need for a floor?
How many tiles you need for an area, with waste and cost per m².
Quick answer
Tiles needed = ceil(area × (1 + waste%) ÷ tile area). A 20 m² floor with 10% waste and 60×60 cm tiles (0.36 m² each): 20 × 1.10 ÷ 0.36 = 61.1 → 62 tiles. Always round up — you cannot buy half a tile.
Tiles to buy
62 pieces
- Area including waste
- 22 m² (237 sq ft)
Suggested waste: 10% for straight layouts, 15% for diagonal layouts or irregular rooms.
How it works
Waste covers cuts along walls and breakage. Use 10% for straight layouts in rectangular rooms; 15% for diagonal patterns or irregular shapes. Keep a few spares for future repairs — matching batches years later is hard.
Once you know the piece count, budget adhesive and grout separately — they are not in the tile number. Large formats benefit from a tile leveling system to stop lippage; a manual tile cutter pays for itself on bathroom cuts. Order tile adhesive and tile grout from the same range as your tiles for compatible open times.
Before you open the boxes, check two codes printed on the side: shade (or tone) and calibre. Tiles are made in runs, and boxes from different runs differ slightly in colour and by up to a millimetre in size — mixing calibres on the same floor is why joints wander. Buy the whole job in one delivery with matching codes. Then, as you lay, work from three or four open boxes at once rather than finishing one before starting the next: any variation inside the batch spreads out invisibly instead of arriving as a block of slightly different tiles across one corner of the room. Before choosing between two boxes at different prices, run them through the real cost per m² comparison: the cheaper box per piece is often the dearer one per square metre.
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Frequently asked questions
How much extra tile for diagonal layout?+
15% minimum — more cuts along every wall. Complex herringbone patterns can need 20%+. The calculator lets you set waste percentage manually; measure the room twice before locking in a diagonal layout on expensive porcelain.
Large vs small tiles for a small room?+
Large format (60×60, 80×80) means fewer grout lines and fewer pieces to buy, but more waste on small irregular rooms. Small tiles suit wet rooms with more cuts — mosaic sheets can also wrap curved shower trays where large slabs will not bend.
Do I include grout in the tile count?+
Tile count is pieces only. Grout is bought separately by kg based on joint width and tile size. Wider joints use more grout per m² — a 60×60 rectified tile at 2 mm joints needs far less grout than 20×20 at 5 mm.
Rectified tiles — less waste?+
Rectified edges allow thinner grout lines but do not reduce the number of cuts along walls. Waste percentage stays similar; aesthetics improve. You still need the same number of perimeter cuts — only the visible joint width shrinks.
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