Tile Calculator

How to use this calculator

Enter the length and width of the area you're tiling, choose your tile size, and pick a waste allowance based on your layout. For grout, also set the joint width, the tile thickness, and the grout type; the defaults (1/8 inch joints, 3/8 inch tile, sanded grout) suit most floors. For an irregular space, split it into rectangles and run each one, then add the results. The calculator returns the number of tiles, an approximate number of boxes, and the pounds of grout with a suggested bag size.

How this is calculated

The calculator divides your total area by the square footage of a single tile, then adds a waste allowance for cuts and breakage. Straight layouts need less waste (10%); diagonal and herringbone patterns need more (15–20%) because more tiles are cut at an angle. Grout is worked out from the volume of the joints: the joint length per square foot (more for smaller tiles) times the joint width and the tile thickness, converted to pounds using the typical density of the grout type. Wider joints, thicker tile, and smaller tile all raise the total. Epoxy grout comes in kits, so the calculator converts the pounds to kits instead of bags.

Example

A 10 by 8 foot floor is 80 square feet. With 12 by 12 inch tile and a 15% waste allowance, you need 92 tiles, about 8 boxes, and roughly 7 pounds of grout. The same floor in 6 by 6 inch tile takes 368 tiles and about 13 pounds of grout, and in 24 by 24 inch tile just 23 tiles and about 4 pounds.

Buying tip

Box coverage varies by manufacturer — always check the actual sq ft per box printed on the product, and round up to the nearest full box. Buying 1 extra box beyond this estimate is common practice in case of future repairs, since dye lots change over time. Buy all your tile at once, and check that every box has the same lot number.

Backsplashes and other small areas

For a kitchen backsplash, the backsplash calculator uses the wall length and height directly and also gives a cost estimate.

Grout estimate is based on manufacturer coverage charts plus about 10% for waste and cleanup. Real usage varies with joint depth, tile edges, and how you mix and clean — check your grout manufacturer's coverage chart.