How to Estimate Floor Tile Quantities

Step 01

Measure the area you will actually tile.

Measure each rectangle at floor level, in metres, and add the sections together. Include alcoves that will be tiled and exclude areas that will not receive tiles, such as fitted units you are keeping.

Write the measurements down before calculating. It is easier to spot a wrong dimension in a worksheet than in a final order.

Step 02

Understand the tile calculation.

The waste allowance covers cuts at walls, doorways, pipes and layout patterns. The calculator keeps the allowance editable because straight layouts, herringbone and diagonal patterns produce very different waste.

• Floor area = length × width, summed across sections.
• Tile area = tile length × tile width, converted to square metres.
• Tiles needed = floor area × (1 + waste rate) ÷ tile area, rounded up.
• Boxes = tiles needed ÷ tiles per box, rounded up.

Step 03

Worked example: a 4 m × 3 m room with 30 cm tiles.

The measured area is 12 m². With a 10% waste allowance the required area is 13.2 m². Each 30 cm tile covers 0.09 m², so about 147 tiles are needed; at 10 tiles per box that is 15 whole boxes.

Changing the layout changes the result. A herringbone pattern with 15% waste raises the required tiles to about 154, and the box count stays the same only because the rounding still falls within 15 boxes.

Step 04

Choose a realistic waste allowance.

Batch numbers matter. If you run short and order again later, a different batch can differ visibly in colour or shade.

• Straight layouts with few cuts: 5–10%.
• Diagonal layouts: 10–15%.
• Herringbone or chevron: 15% or more.
• Rooms with many pipes, corners or irregular shapes: add extra.
• Keep a few spare tiles from the same batch for later repairs.

Step 05

Order whole boxes and verify the product coverage.

Tiles are usually sold in whole boxes with a stated number of tiles or square metres. Use the coverage printed on the product, not a generic estimate, and round up to whole boxes.

The calculator returns a planning quantity, not a binding order. Confirm the product, batch, coverage and layout before purchasing.