Tile Calculator
Tiles, boxes, grout and adhesive for a floor or wall, with waste allowance.
About this tool
Enter the area (or length and width), the tile size in millimetres, the grout gap, the tile thickness, a waste percentage and tiles per box. The tool returns the exact tile count, the number to buy with waste, boxes, and rough grout and adhesive quantities.
Buying the right amount, once
Tiles are sold by the box and by the batch, and both matter: run out and the replacement box may be a slightly different shade, so the waste allowance is not optional. Ten percent covers a straight lay in a simple room; fifteen for diagonal or herringbone patterns and rooms with many cuts; more for large-format tiles where each cut wastes more. The calculation adds the grout gap to each tile's footprint (a 600 ร 300 tile with a 3 mm joint covers 603 ร 303), divides the area and rounds up. Grout is estimated from joint length, width and depth and adhesive at 3โ4 kg/mยฒ, both of which the manufacturer's bag will refine. Measure the room in metres and the tiles in millimetres as printed on the box. The paint calculator covers the walls above, the area calculator handles L-shaped rooms, and the unit converter translates inches.
Frequently asked questions
How much extra should I buy?
10% for a straight pattern, 15% for diagonal or herringbone, 20% for complex rooms. Keep a few spares from the same batch for future repairs.
Do I include the grout gap?
Yes โ the tool adds it to each tile's footprint. A 3 mm gap on small tiles changes the count noticeably; on large tiles hardly at all.
How much grout do I need?
The estimate uses joint length ร width ร depth ร density. Real usage depends on how much you waste; check the coverage table on the grout bag.
What about wall tiles?
Same calculation โ enter the wall's height and width as the area. Do each wall separately and subtract windows and doors.