Flooring and tile calculator

How to use it

1. Enter the room's length and width in feet, or its total area if you already know it.
2. Pick a waste allowance. 10% suits most rooms; use 15% for diagonal or herringbone layouts, or rooms with lots of corners.
3. Enter the coverage per box from the product label to get the number of boxes.
4. For tile, enter the tile size in inches to get the number of tiles.

How it's calculated

1. Floor area = length × width.
2. Amount to buy = floor area × (1 + waste percentage).
3. Boxes = amount to buy ÷ square feet per box, rounded up.
4. Tiles = amount to buy ÷ (tile width × tile length ÷ 144), rounded up. There are 144 square inches in a square foot.

Tile size	Square feet per tile	Tiles per 100 sq ft
12 × 12 in	1	100
12 × 24 in	2	50
18 × 18 in	2.25	about 45
24 × 24 in	4	25

Tile counts don't include grout lines, so they slightly overestimate, which works in your favor.

Measuring an L-shaped or odd room

Split the floor into rectangles, work out each one's area (length × width), add them up, and enter the total in Or total area. Include closets and the floor under appliances that sit on the new floor.

Why buy extra?

Every row ends with a cut piece, some pieces break, and patterns need matching. Extra flooring also covers future repairs: a spare box from the same production batch matches far better than one bought years later. If you have leftovers, keep at least a few pieces.