Measure the floor as non-overlapping rectangles, subtract areas that will not be covered, and enter the coverage printed on the actual box. The job sheet keeps your cutting/spares allowance separate from the extra area created by buying whole boxes. Neither is a prediction of what an installer will actually discard.

What the box count means

The calculation is net area × (1 + allowance ÷ 100), divided by coverage per box and rounded up. The starting example uses 100 square feet, an explicitly chosen 10% allowance and 20 square feet per box. Its 110-square-foot target requires 6 boxes, covering 120 square feet.

The result has two different surplus figures: 10 square feet above the allowance target, or 20 square feet above the measured floor. Calling both figures “waste” would conceal what you planned and what box rounding added. The exported sheet records both.

An optional price field multiplies your entered price by the box count. Leaving it empty means cost is unknown, not zero. The tool does not fetch offers or add tax, delivery, underlayment, adhesive, grout, trim or labor.

Confirm the product and layout first

Daltile’s pattern guidance treats pattern choice and rounding as part of planning. A diagonal layout, mixed-size pattern, narrow perimeter cut or spare-tile requirement can change what needs to be ordered. This area calculator does not determine those pattern ratios or prescribe one allowance for every product. The initial 10% is a worked-example input that you can replace.

Check whether the carton figure is in square feet or square meters, and whether different colors or sizes need separate orders. Use separate sheets for products with different box coverage. Do not substitute nominal tile dimensions for the manufacturer’s stated coverage without checking what the carton contains.

Measure without double-counting

Divide an L-shaped room into rectangles that meet at an edge. An exclusion must fall within the included floor and must not overlap another exclusion. The tool detects deductions larger than the total; it cannot reconstruct your floor plan to detect every overlapping measurement.

Subfloor condition, moisture limits, movement joints, pattern direction and installation-system requirements need their own checks. A sufficient box count does not establish that the material is suitable for the room. Keep a measured layout and the installation instructions with the purchase sheet.

CSV and print record the inputs and results in this tab. In metric mode, enter rectangle dimensions in meters and coverage per box in square meters. Switching the unit selector does not convert existing values.

Source and method

Desk research and an original quantity worksheet, checked October 15, 2026. The worked examples demonstrate arithmetic, not an installation test or recommended product.