Tile & Grout Calculator — ft, in to tiles, bags, cost
How to use this calculator
Enter room dimensions in feet, inches, and fractions. Choose the area shape (rectangle, L-shape, or direct area in ft²), select your tile size and layout pattern. Waste is auto-adjusted by pattern. Results update instantly with tile count, thinset, and grout bags.
Cost — price per tile or per box, thinset per bag, grout per bag, backer board per sheet.
Thinset — 50 lb bag covers ~80 ft² at ¼" × ¼" trowel notch.
Grout — 25 lb bag covers ~90 ft² for 12×12 tile with ⅛" joint.
Backer board — 3×5 ft cement board sheets.
Saved Calculations
| Time | Shape | Area ft² | Tile | Tiles | Thinset | Grout | Backer | Total |
|---|
How to Calculate Tiles, Grout, and Thinset
This tile and grout calculator estimates the number of tiles, thinset mortar bags, grout bags, and cement backer board sheets for rectangular, L-shaped, or custom area rooms. Enter dimensions in feet, inches, and fractions. Select from standard tile sizes (4×4, 6×6, 12×12, 12×24, 18×18, 24×24 inches) or enter custom dimensions. Choose a layout pattern — straight grid, diagonal (45°), herringbone, or brick offset — and waste is auto-adjusted.
Thinset Mortar Coverage
Coverage depends on trowel notch size: ¼"×¼" square notch covers ~80 ft² per 50 lb bag, ¼"×⅜" covers ~60 ft², and ½"×½" covers ~50 ft². Larger tiles and uneven substrates require more mortar per ANSI A108.
Grout Volume Formula
Grout volume = (joint width × tile thickness × total joint length) / coverage factor. A 25 lb bag of sanded grout covers approximately 90 ft² for 12×12" tiles with ⅛" joints. Wider joints or smaller tiles use more grout.
Backer Board
Cement backer board (CBU) sheets are 3×5 ft (15 ft²). The calculator adds 10% for overlap and cutting waste per ANSI A108.11 / TCA Handbook requirements for wet areas.
