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Floor Tiles – Calculations

By · July 1, 2011 · Filed in Floor Tiles

how many 9-inch-square floor tiles are needed to cover a rectangular floor that measure 12 feet by 15 feet?

12 x 15 = 180 sq ft = 25920 sq in

25920 / 81 = 320

But account for waste and broken tiles.

Comments

(3/4)² = 9/16. This is the area of a tile, in square feet.

12′ x 15′ = 180 ft²

180 / (9/16) = 180*16/9 = 20*16 = 320
References :

12 x 15 = 180 sq ft = 25920 sq in

25920 / 81 = 320

But account for waste and broken tiles.
References :

MATH SAYS 320 but this does not allow for waste NOTE the tiles will be in a grid of 15 x 20 ( as opposed to 12 x 15 for 12" tiles ) don’t use square foot calculations for tiles just divide by the size ( in this case the area is 144" x 180" divide both numbers by 9 to get the ‘grid’ of 15 x 20 then multiply the grid for number of tiles – this works well and if you have a partial tile it shows up – it doesn’t just using square foot )

( if your diminsions were 3" wider say 12′ x 15′ 3" a square foot calculation would have you cutting tiles into thirds – the grid method tells you you need another row )

AS FOR the oddball answer – measure your tiles and you will find that they are already cut to allow for the grout line
References :

The tile, including a grout line of 3/16" (standard) covers an area 84.41 square inches. The area to be covered is 25,920 square inches. Therefore, it will take 307 tiles to cover the floor.
References :

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