Tile quantity: grid counts, layout allowance and whole packs.
What does a rectangular tile grid estimate include, and when does a diagonal layout need a separate model?
A grid count differs from an area ratio
The Tile Calculator rounds row and column positions separately, using the entered tile dimensions and joint width. A position at an edge counts as a tile even when it would be cut. Dividing room area by tile area can miss that distinction.
Compare allowances without prescribing one
Using the same illustrative 16-tile base, 10% allowance gives ceil(17.6) = 18 tiles and five four-tile packs. A user-supplied 25% scenario gives 20 tiles and also five packs. The purchase can stay the same even when the internal quantity changes.
Treat diagonal layouts as a different model
A diagonal pattern changes intersections and edge cuts. Do not describe a rotated pattern as a rectangular grid with a universal extra percentage. The separate Rotated Tile Grid Takeoff accepts the supplied rotation and grid origin, clips tile positions to the measured rectangle, and counts every position with positive covered area as a source tile. It does not share offcuts or optimise the pattern. An edge touch with no covered area is excluded. Compare that conservative takeoff with your established cut-reuse plan rather than adding an arbitrary percentage.
Check the pack total
In the 10% example, 20 purchased tiles minus 18 allowed tiles leaves two tiles beyond the allowed quantity. This is different from the four extra tiles above the 16-position grid. Keeping both numbers visible avoids applying the same allowance twice.
Use the matching calculator
Use this decision sequence
- Record measured sections and the selected tile dimensions.
- Enter the specified joint width and grid orientation in the matching model.
- Keep the modelled tile count separate from an entered quantity allowance.
- Round the resulting tile count to the supplied pack count.
Keep the quantities distinct
| Quantity or assumption | How to use it |
|---|---|
| Rectangular grid | Counts rows and columns; partial edge positions count as tiles. |
| Rotated grid | Counts positive-area intersections with the measured rectangle, without cut reuse. |
| Allowance | A supplied extra quantity, not proof of a feasible layout. |
Worked comparison
For a 2 m × 2 m rectangle, illustrative 0.5 m × 0.5 m tiles and a zero joint input, the grid is 4 × 4 = 16 tiles. A supplied 10% allowance rounds to 18 tiles. Four tiles per pack require five packs: 20 purchased tiles.
Check before using the estimate
Zero joint width is an arithmetic example, not an installation recommendation.
All dimensions, product properties, prices and specifications in this example are illustrative arithmetic inputs. Use the values from your measured plan, selected product data sheet and supplier quote. This guide does not choose construction specifications or certify safety.
Calculation and scope checked 2026-10-13. Methods and scope.