Tile quantity calculator
Enter the room or bathroom sizes (or the flat area), the tile size and the m² per box. You get the metres to buy, the boxes, the skirting and the adhesive.
Tile quantity calculator · Qidda
Floors
Walls to tile
Flat
Tile and box
Extras
The result appears here.
Calculated at qidda.app/en/tools/ · Qidda: fit-out project accounts · approximate
How to use the calculator
- Choose where: a room floor, bathroom or kitchen walls, or a whole flat, and enter the sizes.
- Choose the tile size, enter the m² per box from the box itself and pick the layout for the waste.
- Turn on skirting and adhesive and adjust the figures if needed.
- Read the metres, boxes and tile count, and open "How we calculated" for the formula.
The formulas
area = sum of floor areas | sum of (perimeter x height - openings) area_w = area x (1 + waste) boxes = ceil(area_w / m2_per_box) tiles = ceil(area_w / tile_area) skirting_m = sum of perimeters - door widths adhesive_kg = area x kg_per_m2 bags = ceil(adhesive_kg / bag_kg)
Worked example: a 4 x 4 m floor
60 x 60 cm tiles, 1.44 m² per box, straight layout with 10% waste:
- Area 4 x 4 = 16 m², with waste 17.60 m²
- Boxes: 17.60 / 1.44 = 12.2, so 13 boxes (18.72 m²)
- Tiles: 17.60 / 0.36 = 48.9, so 49 tiles
- Adhesive at 4 kg/m²: 16 x 4 = 64 kg, so 4 bags of 20 kg
A 100 m² flat with an 85% net ratio and 10% waste needs 85 x 1.10 = 93.5 m², which is 65 boxes of 1.44 m² for the floors. Bathroom and kitchen walls are calculated separately.
Waste by layout
The common figures attributed to TCNA guidance on tile retailers' pages: about 10% for a straight layout and 15 to 20% for diagonal, large-format or complex patterns. They are guidance, not a rule, and you can edit them here. Ask the seller to supply all boxes from one batch (same grade and shade) and keep a spare box for repairs.
Skirting and adhesive
Skirting is measured in length: room perimeter minus door widths, divided by the piece length, plus 5% for corner cuts. Adhesive is roughly 2 to 5 kg/m² depending on the trowel notch (Mapei Keraflex data sheet); the default here is 4 and you can change it.
Why is the m² per box empty?
Packing differs between factories even for the same size; 60 x 60 is often 4 tiles (1.44 m²) but not always. So we ship no per-brand table: read the number on the box, or enter the tiles per box and we multiply by the tile area.
FAQ
How do I calculate how many m² of tile I need?
Multiply length by width for each room and add them up, add 10% waste for a straight layout (15 to 20% for diagonal or large formats), then divide by the m² per box and round up.
How much tile for a 100 m² flat?
A 100 m² flat is not 100 m² of floor. With an 85% net ratio and 10% waste you need about 94 m² for floors (65 boxes of 1.44 m²), plus bathroom and kitchen walls separately.
How many m² in a box of 60 x 60 tiles?
Often 4 tiles, which is 1.44 m², but packing differs between factories. Read the number printed on the box.
How do I calculate tile for a shower wall?
Perimeter x tiling height, minus the door and window, plus waste. For a 2 x 2.5 m bathroom tiled to 2.4 m: 9 x 2.4 = 21.6 m² minus the door.
Should I buy all boxes at once?
Yes, from one batch (same grade and shade) so there is no visible difference, and keep a spare box for repairs.
Sources
- Tile waste guidance (10% straight, 15 to 20% diagonal or large format, attributed to TCNA): www.tilemountain.co.uk/blog/how-many-tiles-do-i-need/ (accessed 2026-11-13; also cletile.com and tileshoppes.com)
- Miqatona tiles tool: miqatona.com/tools/construction/tiles (accessed 2026-11-13; 60 x 60 often 4 pieces, packing differs)
- Mapei Keraflex technical data sheet: mapei.com/sg/en/products-and-solutions/products/detail/keraflex (accessed 2026-11-13; 2 to 5 kg/m² by trowel notch)
- My Home Egypt cost calculator: myhomeegypt.net/cost/ (updated 2026-10-15; net area 85% of contract area)