materials calculator
Tile Calculator (Metric)
The metric Tile Calculator uses millimetres, centimetres, metres, or square metres as shown beside each field. It applies tiles = adjusted area ÷ tile face area, places a complete metric result in the served HTML, and updates locally in the browser. Verify field measurements, local standards, material data, and structural assumptions before construction.
Calculated result
43 tiles
The adjusted area divided by one tile face gives the tile count, then whole boxes are ordered from the tiles-per-box figure printed on the carton. Diagonal or patterned layouts need a larger waste allowance.
- Boxes
- 5
- Tile face area
- 0.360 m²
- Adjusted area
- 15.4 m²
Printable result and cut list
| Item | Value | Job note |
|---|---|---|
| Primary result | 43 tiles | Verify before cutting or ordering. |
| Boxes | 5 | Calculated from the entered dimensions. |
| Tile face area | 0.360 m² | Calculated from the entered dimensions. |
| Adjusted area | 15.4 m² | Calculated from the entered dimensions. |
| Formula | Expression | Note |
|---|---|---|
| Primary formula | tiles = adjusted area ÷ tile face area | Round the final result, not each intermediate value. |
How the tile calculation works
Enter the job dimensions in the form. The calculator normalizes the values, applies tiles = adjusted area ÷ tile face area, and updates the main result, supporting values, diagram labels, and print table together.
The first displayed example is calculated during the static build. That makes the formula and a complete numerical result readable in page source, while the browser script handles later input changes.
Worked example
The prefilled values form a complete tile and box quantity example. Change one field at a time and compare the updated result with the formula table to catch unit or transcription mistakes.
Common errors to avoid
- Mixing nominal and actual material dimensions.
- Entering diameter where the formula expects radius, or total run where it expects one tread.
- Rounding every intermediate value instead of rounding the final purchase or cut quantity.
- Treating a planning result as a stamped structural design or local-code approval.
How much waste to allow
| Layout | Allowance | Why |
|---|---|---|
| Straight grid, square room | 10% | Perimeter cuts only |
| Offset or brick bond | 10–15% | Every course starts with a cut |
| Diagonal (45°) | 15–20% | Two cuts per perimeter tile |
| Herringbone or mosaic | 20%+ | Complex cuts and breakage |
| Large-format over 24 in | 15% | Cuts and breakage cost more |
Always order full boxes and keep the spare tiles. Production batches shade differently, and a replacement bought a year later rarely matches the floor already laid.
Adhesive and grout planning
- Thin-set adhesive coverage depends on trowel notch, not on tile count — read the bag for the notch being used.
- Grout use rises as tiles get smaller and joints get wider; mosaic sheets can need several times the grout of large-format tile.
- Uneven substrates absorb far more adhesive than a flat, primed screed.
- Movement joints, thresholds, and trim pieces are separate order lines.
Frequently asked questions
Does the tile calculator work without JavaScript?
The default worked result, formula, diagram, and result table are included in the served HTML. JavaScript is only needed to recalculate after you change an input.
Which unit should I use?
Use the imperial page for US customary inputs or open the metric twin for millimetres, centimetres, and metres.
Can I use the result for purchasing material?
Use it as a quantity and layout check, then add the stated waste allowance and confirm package coverage, stock dimensions, and field conditions.
Does this replace building code or an engineer?
No. The calculator is a planning aid. Current local code, product documentation, and a qualified engineer govern structural and life-safety decisions.
How many 12 × 12 tiles do I need per square foot?
Exactly one, because a 12 × 12 in tile is 1 ft². For a 150 ft² floor with a 10 percent allowance, order 165 tiles, then round up to whole boxes.
How many 600 × 600 mm tiles cover a square metre?
Each tile covers 0.36 m², so a square metre needs 2.78 tiles. A 14 m² room with 10 percent waste needs about 43 tiles.
How much extra tile should I buy?
Ten percent covers a straight grid layout; allow 15 to 20 percent for diagonal or herringbone patterns, and keep at least a few spare tiles from the same batch for future repairs.
Related pages
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iPhone companion
Keep jobsite math available offline
The website calculators and charts stay free. The BuildMath iPhone app keeps its supported construction calculations available when the jobsite has no connection.
View BuildMath on the App StoreLast reviewed .