How to use this calculator
Enter the area to cover and the dimensions of a single tile. Use the number of tiles per carton from the supplier, then set an allowance for cuts and breakage. Measure each section of an irregular floor separately and add the areas.
The formula
A worked example
For 120 sq ft using 12 × 12 inch tiles and 10% waste, you need 132 tiles. At 10 tiles per box, buy 14 boxes containing 140 tiles.
Assumptions & limitations
This is an area estimate, not a cutting layout. It does not subtract grout joints or account for staggered and diagonal patterns. Check carton coverage and nominal versus actual tile dimensions.
Common questions
Why are there extra tiles after adding waste?
You can usually buy only whole boxes. Box rounding may add spare tiles beyond your waste allowance.
Does this include grout spacing?
No. The estimate uses the full tile area and ignores grout joints. Confirm the final layout before ordering.
Units reference
The calculation follows the method above. This reference supports the units and conversions.
NIST: units and conversion factors ↗Formula and worked example checked against automated test cases. About our methodology.