Tile Calculator
Find out how many tiles and boxes to buy for a floor or wall — for any tile size, with a waste buffer and a cost estimate.
Enter the floor or wall length & width
Tip: use ~10% waste for straight layouts, ~15% for diagonal or herringbone.
Estimate only. These figures help you plan how much to buy — they are not engineering or structural advice. Actual needs vary with site conditions, waste, and installation method, so order a little extra and confirm final quantities with your supplier or contractor before you buy or start the job.
Popular floor sizes
Jump to a ready-made answer for a common floor.
How the tile calculation works
Divide the area you're covering (plus waste) by the area of one tile.
Room = length × width (ft). Or enter the square footage directly.
(tile width × tile height in inches) ÷ 144 = square feet per tile. A 12 × 12 in tile = 1 sq ft.
Area × (1 + waste) ÷ tile area, rounded up. Add ~10% waste (15% for diagonal).
Tiles ÷ tiles-per-box, rounded up. Tile is usually sold by the box.
Sources & assumptions
Frequently asked questions
How many 12x12 tiles do I need for a 120 square foot room?
A 12 × 12 inch tile covers exactly 1 square foot. For 120 sq ft with 10% waste you need about 132 tiles (120 × 1.10 ÷ 1). Always round up and buy from one batch.
How do I calculate how many tiles I need?
Find the area to cover in square feet, add a waste buffer (about 10%), then divide by the area of one tile. A tile's area in square feet is (width × height in inches) ÷ 144.
How much extra tile should I buy for waste?
Add about 10% for standard straight or grid layouts, and around 15% for diagonal, herringbone, or rooms with many cuts. Buying a little extra also gives you spares for future repairs.
How many tiles come in a box?
It varies by tile size and brand — small mosaics may be 5–11 per box while large-format tiles can be just 3–6. Enter the count from your tile's box to get the number of boxes you need.
Why buy tile from the same lot?
Tile color and shade can vary slightly between production runs (lots or batches). Buying all your tile, plus spares, from a single lot keeps the finished surface uniform.