How to use this calculator
Tile is bought by the box, and pattern waste is real: cuts at edges and pattern repeats consume tiles that never appear on the floor. This tool applies your waste figure once, then rounds up to whole boxes using the actual label coverage of the product you will buy.
Enter your own figures in the form above. A blank field is treated as missing — not as zero — so the tool will ask you to complete it. A genuine zero is accepted where it makes sense (for example, no HOA dues). Press Calculate for a breakdown, Load worked example to fill in the example below, or Reset to return to the defaults.
Formula and assumptions
Order area = net area × (1 + waste %). Boxes = order area ÷ box coverage, rounded UP. Purchased coverage = boxes × coverage. Cost = boxes × box price.
Worked example
Worked example: net 100 ft², 10% waste, 12.5 ft² per box. Order area 110 ft²; 9 boxes; purchased coverage 112.5 ft². The 2.5 ft² surplus is the box-rounding remainder — useful as spares.
Use the Load worked example button above to reproduce this example in the form, then change one input at a time to see what drives the result.
Limitations and common mistakes
This is the coverage mode (area-based). A tile-count mode using individual tile face area and grout joints is a separate calculation for patterned or mixed-size layouts; do not force those layouts into a single coverage figure without checking the pattern repeat. Irregular rooms need area measured in sections.
Frequently asked questions
How much waste for a diagonal layout?
More than straight — often 15% or more depending on room shape and tile size. The waste input is yours; this tool does not assert a universal rate.
Should I keep spare tiles?
Yes. Dye lots change, and a box of spares is far cheaper than a mismatched repair later.
Does grout width change the box count?
In coverage mode, no — label coverage already reflects the product as sold. In tile-count mode, grout joints change the count and must be modelled explicitly.
Sources
No external price, product or market data is used on this page. Every price, density, coverage and rate is a figure you enter, or a clearly labelled illustrative default in the form. Check product labels and supplier quotes for the figures that apply to your job.
Estimates only. Results from this calculator are not a loan offer, appraisal, engineering design, equipment selection or contractor quote.