Tile Calculator
Measure your project, allow for cuts, round up to whole boxes, and plan grout, thinset and local costs.
Behind the numbers
How the tile calculation works
Required coverage = net area × (1 + waste % ÷ 100)
Tile count = required coverage ÷ tile area, rounded up
Boxes = required coverage or tile count ÷ package quantity, rounded up
DIYSum combines your sections before purchase rounding. This prevents each room or wall from being rounded to a separate box unless you choose to calculate them separately.
Grout and thinset use the coverage printed on the product and round up to whole bags.
Example: a 10 × 12 ft floor
The floor is 120 sq ft. With 10% waste, plan for 132 sq ft. A 12 × 24 in tile covers 2 sq ft, so that is 66 tiles. At 8 tiles per box, buy 9 boxes / 72 tiles, covering 144 sq ft.
Before you buy
Confirm actual box coverage, dye lot, tile pattern and manufacturer guidance. Keep extra matching tile when practical for future repairs.
Tile planning questions
How much extra tile should I buy?
There is no universal percentage. A 10% allowance is a common planning starting point, but diagonal layouts, patterns, breakage and difficult cuts can require more.
Should I subtract doors and windows?
You can enter excluded areas for openings you will not tile. For small openings, some installers prefer not to subtract them because cuts can consume similar material.
Why does DIYSum round boxes up?
Retail tile is normally purchased in whole boxes. DIYSum calculates the material requirement first, then rounds the package count up.
How are grout and thinset estimated?
Enter the coverage shown on your chosen product. Coverage varies with tile size, joint dimensions, trowel and substrate.
Project planning examples
Tile planning examples for common projects
These are worked examples, not automatic inputs. Enter your own measurements and supplier packaging in the calculator above.
10 × 10 ft floor
A 100 sq ft floor with a 10% cutting allowance has a coverage target of 110 sq ft. If each box covers 15 sq ft, round 110 ÷ 15 up to 8 whole boxes. Actual waste and box coverage vary.
Kitchen backsplash with outlets
Measure the backsplash sections, account for openings as appropriate, and enter the exact tile size and box coverage. Patterns and difficult cuts may increase the allowance.
Verify tile box coverage, layout and substrate requirements. Grout and thinset quantities depend on the actual product, joint width and trowel; use manufacturer coverage values.
Related tools: Square footage · Cubic yard · All DIY calculators.