Tile Calculator With Grout. Tile calculations require pattern consideration and waste factors. Formula: Tiles Needed equals Floor Area divided by Tile Size times Waste Factor. Standard waste: straight lay 10 percent, diagonal 15 percent, complex patterns 20-25 percent. Calculate area: Length times Width in square feet. Convert to tile count based on tile dimensions. Common sizes: 12×12 inch tiles cover 1 sq ft each, 18×18 tiles cover 2.25 sq ft, 24×24 tiles cover 4 sq ft, 6×6 tiles cover 0.25 sq ft. Example bathroom: 10×12 ft equals 120 sq ft. Using 12×12 tiles: 120 tiles needed. Add 10 percent waste equals 132 tiles for straight pattern or 138 for diagonal. Grout calculation depends on tile size, joint width, tile thickness. Standard joints: floor 1/4 inch, wall 1/8 inch. Formula: (Tile Length plus Width) divided by (Length times Width) times Joint Width times Depth times 1.8 equals pounds per square foot. Sanded grout for joints over 1/8 inch, unsanded for smaller. Pattern affects waste dramatically: Straight grid lowest at 10 percent, running bond (brick) 10-12 percent, diagonal 15 percent, herringbone 15-18 percent, Versailles 20 percent due to cuts. Cost ranges: Budget ceramic 50 cents to 2 dollars per sq ft, mid-grade porcelain 2-7 dollars, premium stone 7-20 dollars, designer 15-50 dollars per sq ft. Professional installation 5-15 dollars per sq ft. Materials beyond tiles: thinset mortar 1 bag per 80-120 sq ft, spacers, sealer for stone. Example kitchen backsplash: 4 ft high by 20 ft long equals 80 sq ft. Using 3×6 subway tiles at 0.125 sq ft each: 640 tiles base. Running bond adds 12 percent: 717 tiles total. Typically 48 per box needs 15 boxes. Cost at 2 dollars per tile: 1,434 dollars materials. Grout 12 pounds. Installation 800 dollars. Total 2,300 dollars. Common mistakes: not accounting pattern waste, measuring feet then calculating inches without conversion, forgetting thresholds, ordering exact without waste. Pro tips: order 15-20 percent extra for discontinued, buy same lot number, dry lay first, start from center, use large format to reduce grout lines. Floor vs wall: floor thicker and slip-resistant, wall lighter. Porcelain works both. Moisture areas need cement board and waterproof membrane. Grout types: sanded for 1/8 inch plus joints, unsanded for smaller, epoxy for counters. Seal natural stone before and after grouting. Cost breakdown 100 sq ft: tiles 400, thinset 30, grout 40, backer 100, membrane 75, supplies 50, total materials 695, labor 800-1,200.