Tile Calculator

Use this tile calculator to estimate how many tiles are needed for a rectangular room or surface. It accounts for room area, tile size, grout gap, and waste.

Formula

$N=\left\lceil\frac{A_{room}(1+w)}{A_{tile}}\right\rceil$

The tile module area includes the tile dimensions plus the grout gap. The final count is rounded up because partial tiles still require full tiles.

Example

A 12 ft by 10 ft room has 120 square feet of area. With 10% waste:

$120 \times 1.10 = 132\text{ sq ft}$

If each tile module is about 1 square foot, the estimate is 132 tiles.

Waste guidance

Common waste factors:

Limits

This estimates tile count, not thinset, grout volume, underlayment, trim, or labor.

Sources and further reading

• Wikipedia: Area - the area of a rectangle (length x width) used for both the room area and the tile module area.
• Wolfram MathWorld: Ceiling Function - the round-up step that turns a fractional tile count into whole tiles.
• TCNA Handbook for Ceramic, Glass, and Stone Tile Installation (Tile Council of North America) - the industry standard behind the layout-pattern and waste guidance; common practice is roughly 10% overage for straight grids and more for diagonal patterns or layouts with many cuts.