Read before you buy
A deeper planning guide
Use these notes to check the assumptions behind the estimate and decide what to verify at the store or on site.
Measure Floors and Walls
Measure each rectangular section at its finished surface. For a floor, take the longest dimensions in the direction of the room and sketch alcoves, closets, columns, and fixed cabinets. For a wall, measure width and height separately. Add the areas of separate rectangles before estimating one combined order; this keeps the package rounding from multiplying unnecessarily across small sections.
Doors, cabinets, and fixtures are not automatically subtracted by this basic tool because the usable offcuts depend on tile layout. A large opening may save material, while several small openings can still require nearly the same number of tiles. Use the area estimate to plan the order, then check the first and last rows on a layout sketch.
Nominal Tile Size and Grout Joints
Enter the nominal tile dimensions printed on the product package. The calculator converts the tile area into the surface unit before dividing. It does not subtract grout joints, because the joint width, layout direction, edge cuts, and installation system vary. The nominal area produces a practical material estimate; it is not a replacement for a row-by-row layout.
Tile can be sold by piece, box, or coverage. This calculator works from tiles per box and a price per box, so verify that the package count is for the exact size, thickness, and finish you intend to use. Rectified tile, mosaics, and large-format panels may need different handling, leveling products, or layout planning than the simple rectangular assumption here.
Choose a Waste Allowance
The editable waste percentage is applied once to the exact tile count, then the result is rounded up to whole tiles. Ten percent is a reasonable starting point for a straightforward straight lay with a rectangular room. Increase it for diagonal, herringbone, basketweave, strong pattern matching, fragile edges, many corners, or a first installation.
Waste should reflect cuts that cannot be reused, breakage, and a small repair reserve. It should not hide a missing room section or be applied again after the box rounding. If your supplier sells tile only by coverage, compare the box coverage directly with the required area and keep a note of why your chosen percentage fits the layout.
From Tiles to Full Boxes
The calculator first finds the number of whole tiles after waste. It then divides by the tiles per box and rounds up again because an unopened box is the purchase unit. For example, 137 tiles at 12 per box requires 12 boxes, or 144 tiles purchased. The six-tile difference is package surplus, not a second waste percentage.
Price is multiplied by full boxes, so check whether your store accepts unopened box returns and whether replacement tiles will be available later. Keep the box label and batch information until the installation is complete. A small additional reserve can be worthwhile for repairs, but record it separately from the calculator's project quantity.
Check Your Order Before Buying
Confirm the product name, shade, lot or dye batch, thickness, finish, and actual package count. Ask whether the printed coverage assumes a particular grout joint or whether the package count has changed. For wall tile, verify that the substrate and wet-area requirements are met before relying on a quantity estimate.
This tool excludes mortar, adhesive, grout, membrane, edging, spacers, leveling clips, tools, delivery, labor, and tax. It also does not evaluate structural movement, waterproofing, or code requirements. Use the result to prepare a shopping list, then compare it with the manufacturer's installation instructions and a layout that shows where cuts land.
