This tile calculator estimates how many floor or wall tiles you need to buy from room size, tile size, metric or imperial units, and a 10%, 15%, or 20% waste factor for layout complexity.
Inputs and method
Enter room and tile dimensions, a selected planning allowance, and tiles per box. The selected 10%, 15%, or 20% is an input scenario, not a universal installation rule. It is applied to the unrounded area-based tile count; tiles are rounded up once with floating-point tolerance for mathematically exact integers, then boxes are rounded up from that purchase count.
Calculations retain full floating-point precision until the labeled display step. Counts and packages use an explicit upward ceiling only where a whole purchase unit is required.
Interpreting the estimate
Use the result as a planning value and keep input precision consistent with the measurements or source data you have. Small displayed differences can come from final-place rounding; intermediate values are not rounded.
Assumptions and limits
Actual coverage, grout joints, layout, cuts, breakage, pattern matching, and package quantities are product- and project-specific inputs. Measure the room first with the square footage calculator; for the concrete underlayment or slab beneath, see the concrete calculator; and for a complementary masonry material, pair the estimate with the brick calculator.
Empty entries, invalid numbers, prohibited negatives, zero denominators, impossible relationships, and unsupported options trigger a validation message instead of a misleading result.
Sources
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Area measurement — supports SI area units and conversions; the geometric arithmetic is independently derived.
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NIST, “SI Units” — SI unit definitions behind the metric tile and room dimensions.