How to use this calculator
- Set the tile size and joint width, then pick a tile colour and grout colour.
- Choose a pattern and whether to start from a corner or the centre of the room.
- Rotate and zoom the 3D room to see how it looks.
- Enter your room's size to count whole and cut tiles, then open the tile calculator for boxes.
The formula
Every tile is drawn at its real size inside a 6 × 5 m sample room.
Your floor plan counts each tile as whole (all corners inside) or cut (crosses the edge).
Tiles to buy = whole + cut, plus 5 % for breakage.
Counting the real layout is usually more accurate than a flat waste percentage, because it shows how many tiles your edges will actually cut. Offcuts are not reused in the count, which keeps it on the safe side.
Colours on screen are only a guide — always look at a real sample in your room's light before you buy.
Tips before you buy
- Starting from the centre often gives equal cuts on both sides of the room.
- Avoid thin slivers of tile at a doorway — move the start point a little if you see them.
- Herringbone and diagonal layouts look great but create more cuts; the count shows how many.
Frequently asked questions
›Is the 3D view to scale?
Yes. The sample room is 6 m × 5 m with 3.2 m walls, and tiles and joints are drawn at their real size.
›Why are cut tiles counted as whole tiles?
Each cut tile starts as a whole tile. Sometimes an offcut can be used elsewhere, which is a small bonus on top of the count.
›Can I upload a photo of my tile?
Not yet. Tiles are drawn in code so the scale is exact and there are no image rights issues.
Sources
- 3D room geometry adapted from our own 3D visualizer project; tile layouts computed with the same geometry that is unit-tested.
Formulas last reviewed: September 29, 2026. How we check our formulas