How to Use the Tile Calculator
Fill in the fields in the calculator, then select Calculate to show the estimate.
- Enter Area to tile and choose
sq ft,sq m, orsq yd. - Enter Waste / overage %. The default is
10; enter0to exclude an allowance. - Enter Tile length and Tile width. Choose each unit independently from
in,ft,mm,cm, orm. - Enter Grout joint width and choose its unit. Enter
0for no visible joint. - Optionally enter Tiles per box (optional).
- Select Calculate to show the tile estimate, optional box estimate, formula, assumptions, and intermediate values.
- Select Copy result or Download result (.txt) to save the plain-text result.
Select Reset to clear Area to tile and Tiles per box, restore the default waste, tile dimensions, units, and grout width, and hide errors and the previous result.
How the Calculation Works
The script converts the entered area to square feet and tile dimensions and grout width to inches. It then applies these formulas:
Tile module area = (Tile length + Grout width) x (Tile width + Grout width)Area with waste = Area to tile x (1 + Waste % / 100)Tiles needed = ceil(Area with waste / Tile module area)Boxes needed = ceil(Tiles needed / Tiles per box)when Tiles per box is entered.
A wider grout joint increases the modeled footprint of each tile. For example, 100 sq ft with 10% waste and a 12 in x 12 in tile with a 0.125 in grout joint produces a module area of about 1.0209 sq ft and 108 tiles.
Reading and Saving the Result
After a successful calculation, the result shows Tiles needed, optional Boxes needed, Total coverage bought, and Actual overage. It also lists converted values, tile face area, grout width, tile module size and area, quantities, and the formula used.
Total coverage bought is calculated from the rounded tile count and tile module area. If you enter Tiles per box, whole-box purchasing may provide more coverage; the script does not recalculate this figure from Boxes needed.
Select Copy result for a plain-text summary. If clipboard access fails, the calculator displays a manual-copy message. Select Download result (.txt) to download the same summary as a .txt file.
Validation and Calculation Limits
Use values within these ranges:
- Area to tile:
0.1to1,000,000in the selected unit. - Waste / overage %:
0to50. - Tile length and Tile width:
0.1to200in the selected unit. - Grout joint width:
0to5in the selected unit. - Tiles per box (optional): numeric and
1to10,000; the script does not require a whole number.
Invalid input stops the calculation, shows an error, and hides the previous result. The estimate assumes a simple grid layout with uniform grout joints. It does not calculate adhesive, mortar, or grout quantities; fetch pricing or supplier availability; or model room shape, fixture and edge cuts beyond the waste percentage, diagonal, herringbone, or offset layouts, tile lot or shade variation, or substrate condition. Treat the result as a mathematical estimate, not certified tiling or purchasing advice.
Privacy and Local Processing
The calculator script performs the calculation and result generation in the browser and contains no request sending the values entered into this calculator. This narrower statement applies to the calculator script, not every feature loaded on the page.
Frequently Asked Questions
What is the tile calculator formula?
Tile module area = (Tile length + Grout width) x (Tile width + Grout width). Area with waste = Area to tile x (1 + Waste % / 100). Tiles needed = ceil(Area with waste / Tile module area). If you enter tiles per box, Boxes needed = ceil(Tiles needed / Tiles per box). For example, 100 sq ft with 10% waste is 110 sq ft; with a 12 in x 12 in tile and a 1/8 in grout joint, the module area is about 1.0209 sq ft, giving 108 tiles.
Why does grout joint width affect the tile count?
Each tile is modeled with its face area plus roughly one grout joint width added to its length and width. A wider joint increases the area assigned to each tile in the layout, which can change the tile count.
How do I get a box quantity instead of just a tile count?
Enter the number of tiles per box shown on the product packaging in the optional Tiles per box (optional) field. The calculator rounds the tile count up to the nearest whole box. Its coverage figure remains based on the rounded tile count, not the rounded box count.
What units are supported?
Area to tile accepts square feet, square meters, or square yards. Tile length, Tile width, and Grout joint width each accept inches, feet, millimeters, centimeters, or meters, set independently.
Does this tool fetch live pricing or give certified advice?
No. It uses the values you enter and does not fetch material prices or supplier data. It is not certified tiling or purchasing advice.