Quick answer
Tiles = area × 144 ÷ (tile length × tile width) × (1 + waste). 120 ft² of 12 × 12 inch tile with 10% waste needs 132 tiles.
Enter the area, tile size and waste. The calculator returns the number of tiles and the area with waste.
Related tools: Tile Grout Calculator: Volume of grout needed for a tiled area. Cost to Tile a Shower Calculator: Estimated cost from tiled area, material price and labor price. Flooring Calculator: Flooring area with waste, and boxes if you know the coverage per box.
How to use the Tile Calculator
- Enter area to tile (ft²) (above 0).
- Enter tile length (in) (above 0).
- Enter tile width (in) (above 0).
- Enter waste allowance (%) (between 0 and 100). It starts at 10.
- Optionally, enter tiles per box (optional) (above 0).
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Area to tile | A number, in ft² | > 0 |
| Tile length | A number, in in | > 0 |
| Tile width | A number, in in | > 0 |
| Waste allowance | A number, in % | ≥ 0, ≤ 100, starts at 10 |
| Tiles per box (optional) (optional) | A number | > 0 |
Formula and method
Formula
tiles = area × 144 ÷ (tile length × tile width) × (1 + waste)
IEEE-754 double precision; shown to the decimals indicated.
Include the grout joint in the tile size if you want it counted. Plan geometry only; confirm quantities with your supplier and local code before ordering.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Area to tile = 120; Tile length = 12; Tile width = 12; Waste allowance = 10.
| Result | Value |
|---|---|
| Tiles needed | 132 |
| Area with waste | 132 ft² |
| Boxes | — |
Example 2
Inputs: Area to tile = 85; Tile length = 24; Tile width = 12; Waste allowance = 12; Tiles per box (optional) = 8.
| Result | Value |
|---|---|
| Tiles needed | 48 |
| Area with waste | 95.2 ft² |
| Boxes | 6 |
Example 3
Inputs: Area to tile = 40; Tile length = 6; Tile width = 6; Waste allowance = 15; Tiles per box (optional) = 44.
| Result | Value |
|---|---|
| Tiles needed | 184 |
| Area with waste | 46 ft² |
| Boxes | 5 |
The first line is the headline result (tiles needed). Below it the tile Calculator lists area with waste and boxes, which describe the same case from other angles. IEEE-754 double precision; shown to the decimals indicated.
The arithmetic
Each 12 × 12 tile covers 1 ft², so 120 ft² needs 120 tiles; with 10% waste, 132. Smaller tiles, such as 4 × 4, need 9 per square foot.
Waste
Use 10% for straight lays and 15% for diagonals or patterns. Buy an extra box or two for repairs from the same batch. Grout and thin-set are estimated separately.
How the result changes with area to tile
Holding every other input at the first worked example, this table changes only area to tile. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Area to tile | Tiles needed | Area with waste | Boxes |
|---|---|---|---|
| 60 | 66 | 66 ft² | — |
| 120 | 132 | 132 ft² | — |
| 240 | 264 | 264 ft² | — |
| 480 | 528 | 528 ft² | — |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Area to tile: entering "0" shows "Area to tile must be greater than 0." beside that field and no result.
- Tile length: entering "0" shows "Tile length must be greater than 0." beside that field and no result.
Choosing between the Tile Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Tile Grout Calculator](/construction/tile-grout-calculator/) | area, tile length and tile width | Grout volume |
| [Cost to Tile a Shower Calculator](/construction/cost-to-tile-shower/) | area to tile, tile price and labor and setting materials | Estimated cost |
| [Flooring Calculator](/construction/flooring-calculator/) | room length, room width and waste allowance | Flooring to buy |
| [Carpet Calculator](/construction/carpet-calculator/) | room length, room width and roll width | Carpet needed |
| [Roof Pitch Calculator](/construction/roof-pitch-calculator/) | i know the and value | Pitch |
Background: construction estimates
Material quantities are geometry plus a margin. Calculate the exact volume or area, add an allowance for waste, spillage, cuts and uneven ground (calculator pages commonly mention 5 to 10 percent, a rule of thumb that varies by material and job) and round up to whole units. One cubic yard is exactly 27 cubic feet.
Suppliers often have minimum order sizes and may charge for small loads, so confirm quantities, product yields and local code with your supplier or a qualified estimator before ordering.
Assumptions and limitations
- Diagonal layouts need more waste
Quantities are estimates. Add allowances for waste and site conditions, and follow local codes and a qualified professional's instructions for structural or safety-critical work.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for area to tile and tile length to confirm this.
Frequently asked questions
How many tiles per square foot?
144 divided by the tile area in square inches.
Do I add grout joints?
The count ignores joints; grout width is small.
What about large-format tiles?
They need more waste if the room is cut up.
What does the Tile Calculator calculate?
Number of tiles (and boxes) for an area. It returns Tiles needed, Area with waste and Boxes.
What formula does the Tile Calculator use?
tiles = area × 144 ÷ (tile length × tile width) × (1 + waste). Include the grout joint in the tile size if you want it counted.
What do I need to enter in the tile Calculator?
You enter Area to tile (ft²), Tile length (in), Tile width (in) and Waste allowance (%). Optional: Tiles per box (optional).
How is the result rounded or limited?
IEEE-754 double precision; shown to the decimals indicated. Diagonal layouts need more waste.
What is an example of a tile result?
With area to tile 120, tile length 12, tile width 12 and waste allowance 10, the tiles needed is 132.
Can I rely on this calculator for a decision?
Quantities are estimates. Add allowances for waste and site conditions, and follow local codes and a qualified professional's instructions for structural or safety-critical work. For this calculator in particular: Diagonal layouts need more waste.
Related calculators
- Tile Grout Calculator — Volume of grout needed for a tiled area.
- Cost to Tile a Shower Calculator — Estimated cost from tiled area, material price and labor price.
- Flooring Calculator — Flooring area with waste, and boxes if you know the coverage per box.
- Carpet Calculator — Square yards of broadloom carpet for a room, choosing the layout that wastes least.
- Roof Pitch Calculator — Roof pitch as rise per 12 inches, angle, slope percent and rafter length factor.
- Aquarium Volume Calculator — Capacity and filled weight of a rectangular aquarium.
Sources
- OpenStax, Prealgebra 2e (Rice University): perimeter, area, volume, circumference and the Pythagorean theorem
- NIST Special Publication 811, Guide for the Use of the International System of Units (SI), Appendix B conversion factors (international foot 0.3048 m, inch 25.4 mm, US gallon 3.785411784 L)
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.