Tile Calculator

Calculate tiles, boxes, grout, thinset, and cost for floors and walls with pattern waste factors.

Room Length (ft)

Room Width (ft)

Tile Size

Pattern

Tile Cost ($/sqft)

Tiles Needed (10% waste)

132 tiles

14 boxes (10 per box)

Room area	120 sqft
Tile size	12" x 12" (1.00 sqft/tile)
Pattern waste	Straight lay (10%)
Tiles needed	132
Boxes	14
Grout (25 lb bags)	2 bags
Thinset (50 lb bags)	3 bags
Tile cost	$660.00
Total (tile + grout + thinset)	$765.00

info

Mike Callahan: “Diagonal and herringbone patterns waste 15-20% more tile than straight lay. Budget for it or you’ll be making two trips to the tile shop. And always buy from the same dye lot — tiles from different lots look different on the floor.”

Methodology

Tiles needed = ceil(room area / tile area x (1 + waste%)). Box count rounded up to nearest full box. Grout estimated at 1 bag (25 lb) per 100 sqft for standard grout joints. Thinset estimated at 1 bag (50 lb) per 50 sqft using a 1/4" x 3/8" square-notch trowel. Waste percentages: straight 10%, brick/offset 12%, diagonal 15%, herringbone 20%. Actual waste varies with room shape, tile size, and installer skill. Grout and thinset costs estimated at $15 and $25 per bag respectively, 2026 pricing.

Frequently Asked Questions

How many tiles per square foot?

For 12x12 tiles: exactly 1 tile per square foot. For 12x24 tiles: 0.5 tiles per square foot (each tile covers 2 sqft). For 6x24 tiles: 1 tile per square foot. For 18x18: 0.44 tiles per sqft (each covers 2.25 sqft). For 24x24: 0.25 tiles per sqft (each covers 4 sqft). Always add your waste factor on top of the net count.

How much waste for diagonal tile?

Diagonal (45-degree) layouts typically require 15% waste, compared to 10% for straight lay. The extra waste comes from cutting triangles at every wall edge — each wall line intersects tiles at an angle, producing unusable offcuts. Herringbone is worse at 20% because every row requires angled cuts and the small offcuts are rarely reusable. Experienced installers may reduce waste slightly, but always budget the full percentage.

How much thinset per square foot?

A 50 lb bag of thinset covers approximately 50 sqft when applied with a 1/4" x 3/8" square-notch trowel (the most common size for floor tile). Larger tiles (18x18 and up) require a 1/2" x 1/2" trowel, which uses more thinset — roughly 40 sqft per bag. For walls, a 1/4" x 1/4" V-notch trowel covers about 70 sqft per bag. Always back-butter large format tiles for full coverage.

How much grout do I need?

A 25 lb bag of sanded grout covers approximately 100 sqft for 12x12 tiles with 1/8" joints. Larger joints (1/4") or smaller tiles (such as mosaics) use significantly more grout — possibly 2-3x as much per square foot. Unsanded grout is used for joints 1/8" and narrower; sanded grout for wider joints. Coverage varies by tile size, joint width, and tile thickness. Check the manufacturer’s coverage chart for precise estimates.