Interior and Finishing

Tile Calculator

How many tiles you need, from your area and the tile size, with a sensible waste allowance.

Tiles for an area

Enter the area and one tile size. 10 percent waste added.

sq ft
in
in
cm
cm
Tiles
-
Area with waste
-sq ft
tiles = (area × 1.10) ÷ (tile width × height ÷ 144), rounded up
Tiles
-
Area with waste
-
tiles = (area × 1.10) ÷ (tile width × height ÷ 10000), rounded up
Estimate only. Rounded up with a 10 percent waste allowance. Confirm the final quantity with your supplier before ordering.

How the tile estimate works

Work out one tile area, add 10 percent for cuts and breakage, then divide. Diagonal and herringbone layouts waste more, so lean toward 15 percent for those. You will also need thinset and grout sized to the tile and gap, which depend on the specific products, so check their coverage on the bag.

Setting tile? The right notched trowel for your tile size is the single most useful tool for an even bed.

View on Amazon As an Amazon Associate we earn from qualifying purchases.

Common questions

How many 12 by 12 tiles do I need for 100 square feet?

Each 12 by 12 inch tile covers one square foot. With 10 percent waste that is 110 tiles.

How much extra tile should I buy?

About 10 percent for a straight layout, and 15 percent for diagonal or patterned layouts. Keep a few spares for future repairs.
Knowledge Base

Estimating Guides & Reference

Plain-language guides on measuring, coverage and how much extra to buy, written for DIYers and trades.

Measuring & Estimating
Concrete & Aggregate
Soil & Lawn
Interior & Finishing