Tile Calculator

How the tile count works

Each tile covers its own area plus its share of the grout joint, so the joint is added to both tile dimensions.

Worked example: a 12 × 10 ft floor with 12 × 12 in tile

1. Surface area: 12 × 10 = 120 sq ft.
2. Area per tile with a 1/8 in joint: 12.125 × 12.125 ÷ 144 = 1.021 sq ft.
3. With 10% waste: 120 × 1.10 ÷ 1.021 = 129.3, so you need 130 tiles.
4. At 10 tiles per box: buy 13 boxes.

Waste allowance by layout

• Straight or grid layout: about 10%.
• Offset or brick pattern: about 10–15%, depending on the tile size.
• Diagonal or herringbone: about 15–20%, because more tiles are cut at the edges.
• Natural stone or fragile tile: add more, as pieces can arrive chipped or break during cutting.

Large tiles change the math

Waste doesn't only depend on the pattern. With a 24 × 48 in tile in a small bathroom, one cut can use most of a tile, and the offcut may not fit anywhere else. For large formats in small rooms, sketch the layout on paper first, count whole and cut tiles, and treat this calculator's answer as a minimum.

Tile sizes are nominal

A tile sold as 12 × 12 in may measure slightly less. If the product page gives an exact size, use it. Grout joint choice also depends on the tile, so check the manufacturer's minimum, particularly for rectified or large-format products.

Before you order

• Match the lot or shade code on each box, because shades can differ between production runs.
• Keep a few spare tiles for repairs. Matching them years later can be difficult.
• Thinset, grout, backer board and trim pieces are extra, and their coverage is listed on each product.

Finishing the rest of the room? Try the flooring calculator or the paint calculator.