How the tile calculator works
The calculator treats each tile plus its share of the grout joint as a repeating module, divides adjusted area by that module, then rounds up.
It is an area count, not a layout optimizer. Pattern direction, centering, niches and minimum cut sizes determine whether offcuts can be reused.
Formula used for tile calculator
The calculator keeps the measured quantity separate from any purchase rounding or allowance.
- Tile module
(tile width + joint) × (tile length + joint) - Adjusted area
surface area × (1 + cuts allowance) - Tiles
adjusted area ÷ module area, rounded up
Planning choices for tile calculator
| Situation | Use | Why it matters |
|---|---|---|
| Straight stack or running bond | Moderate allowance | Many cuts may be reused |
| Diagonal or feature layout | Layout-specific allowance | Creates more triangular offcuts |
| Tile sold by carton | Convert using carton count | Purchase unit is the box, not one tile |
These are measurement and ordering choices, not structural specifications or code requirements.
Measure and order tile
Measure each tiled plane and subtract only openings that truly eliminate tile. Add niches, returns and tub aprons as their own rectangles.
Check shade and calibre codes on every carton and retain spare matching tile for future repairs.
Tile Calculator questions
Should grout joints reduce the count?
They slightly increase the repeating module. Set the joint to zero if you prefer the conservative bare-face method.
How much waste should I add?
Use the drawn layout, tile fragility, pattern and spare requirement; there is no correct universal percentage.
Does this calculate boxes?
It returns tiles. Divide by the tile count per carton and round up, or use carton square-foot coverage.
Variables and units
For the default “Known area” mode. Other modes label their own fields in the calculator.
area- Area to cover: ft², yd², m².
width- Tile width: in.
height- Tile length: in.
joint- Grout joint: in; optional.
waste- Cuts and breakage allowance: %; optional.
Worked example: 96 ft² with 12 × 24 in tile
A bathroom has 96 ft² of tile area, 12 in by 24 in tiles, a 1/8 in joint and 12% cuts.
| Field | Value |
|---|---|
| Area to cover | 96 ft² |
| Tile width | 12 in |
| Tile length | 24 in |
| Grout joint | 0.125 in |
| Cuts and breakage allowance | 12 % |
| Result | Value |
|---|---|
| Tiles to buy | 53 tiles |
| Area including allowance | 108 ft² |
These figures are generated by the same calculation the calculator above uses, so they update automatically if the method changes.
Where these numbers come from
This calculator uses geometry and values shown in the form. Editable product dimensions, coverage figures, prices and allowances are inputs, not universal recommendations; confirm them against the product label, drawing or supplier quote.
Last updated:
Published by Material Totals. Review the calculation methodology and source registry.
Suggested citation: Material Totals, “Tile Calculator,” https://materialtotals.com/tile-calculator/
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