Tile Layout Calculator

How to use it: enter your room dimensions, the tile size, and the grout gap between tiles, then choose a layout mode. "Start at edge" lines the first tile up flush with one wall, so every cut tile ends up along the opposite wall. "Centered" splits the leftover space evenly between both opposite walls, so the cut tiles at each edge match.

Formula. Tile pitch is the tile size plus one grout gap. The tile count along an axis is the room size divided by pitch, rounded up so the grid always covers the room:

Pitch = tile size + grout gap, Tile count = ceil(room size ÷ pitch)

In centered mode, the space actually covered by that many tiles is count × pitch − gap (the last gap isn't needed past the final tile). Half of the difference between room size and covered size becomes the offset - and the width of the cut tile - at each edge, clamped between 0 and one full tile.

Worked example. With the defaults above (3000 × 2400 mm room, 300 × 300 mm tiles, 3 mm grout, centered mode): pitch = 300 + 3 = 303 mm. Columns: 3000 ÷ 303 ≈ 9.90, rounded up to 10 tiles, covering 10 × 303 − 3 = 3027 mm - 27 mm more than the room, so the clamp puts the width edge cut at 0.0 mm (the grid already spans wall to wall, with that small 27 mm excess split across both edges rather than producing a distinct cut tile). Rows: 2400 ÷ 303 ≈ 7.92, rounded up to 8 tiles, covering 8 × 303 − 3 = 2421 mm - again over the 2400 mm room height, so the height edge cut also reads 0.0 mm. Grid = 10 × 8 = 80 tiles total.

The result above uses these exact values. This snapshot is included when the page is printed so the output can be checked against the original measurements.

Room width

3000 mm

Room height

2400 mm

Tile width

300 mm

Tile height

300 mm

Grout gap

3 mm

Layout

Centered

Primary result: Grid: 10 x 8.

• Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
• Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
• When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.

This is a straight rectangular grid - it does not model diagonal, herringbone, brick-bond, or other offset patterns, and it assumes the room is a perfect rectangle with no obstructions (columns, alcoves, fixtures) to lay out around.

The tile count is the exact number needed to cover the grid with no allowance for breakage, miscuts, or future repairs - add a waste margin (commonly 10% or more for diagonal or intricate patterns) when you actually order tile.

When the tile pitch divides the room size almost exactly, the reported edge cut can round down to 0.0 mm even though a small trim is still needed at the wall - always dry-lay the first row before cutting anything.