How Much Tile Do I Need?
Estimating tile starts with the total area you want to cover. Once you know the floor or wall area, you can add a waste allowance and convert the result into individual tiles or full boxes.
Calculate your tile quantity automatically
Enter your project dimensions, tile size, waste percentage and box coverage to estimate how many tiles or boxes you need.
Use the Tile Calculator Calculate Surface AreaHow to Calculate How Much Tile You Need
The first step is finding the area of the surface that will receive tile. For a rectangular floor or wall:
If a room measures 12 ft by 10 ft:
That gives you the exact surface area before adding material for cuts, breakage and installation waste.
How Much Extra Tile Should You Buy?
Buying exactly the measured square footage leaves no allowance for cut pieces, chipped tiles, pattern alignment or future replacements.
Around 10% extra is commonly used as a planning allowance for a straightforward installation.
More complicated projects may require a larger allowance.
| Tile Layout | Planning Waste | Reason |
|---|---|---|
| Simple straight layout | About 5% to 10% | Relatively simple perimeter cuts |
| Irregular room | About 10% | More corners and cut pieces |
| Diagonal layout | About 10% to 15% | Angled perimeter cuts create more waste |
| Complex pattern | Often 10% to 15% or more | Pattern alignment can require additional cuts |
Tile Calculation Formula
Once you know the surface area, apply your waste percentage:
For example, 120 ft² with 10% waste:
You would therefore plan to purchase enough tile to cover at least 132 ft².
Example: 12 ft × 10 ft Bathroom Floor
Step 1: Calculate the floor area
12 ft × 10 ft = 120 ft².
Step 2: Add 10% waste
120 × 1.10 = 132 ft².
Step 3: Check box coverage
Imagine the selected tile comes in boxes covering 15.5 ft² each.
132 ÷ 15.5 = 8.52 boxes.
Step 4: Round up
You cannot normally buy 0.52 of a box, so round upward to 9 boxes.
How to Calculate the Number of Tiles
If tiles are sold individually, calculate the area of one tile first.
For a 12 in × 12 in tile:
If your project requires 132 ft², you would need approximately 132 tiles of that size.
In practice, most tile is sold by the box, so box coverage is usually more useful for purchasing.
How Many Square Feet Does One Tile Cover?
Convert both tile dimensions from inches to feet, then multiply them.
| Tile Size | Approx. Area per Tile |
|---|---|
| 6 in × 6 in | 0.25 ft² |
| 12 in × 12 in | 1 ft² |
| 12 in × 24 in | 2 ft² |
| 18 in × 18 in | 2.25 ft² |
| 24 in × 24 in | 4 ft² |
These figures represent the tile's nominal surface area. Always use the coverage stated on the product packaging when ordering full boxes.
How Many 12 × 12 Tiles Do I Need?
A 12 in × 12 in tile covers approximately one square foot.
That makes the calculation especially simple.
| Project Area | Exact 12 × 12 Tiles | With 10% Waste |
|---|---|---|
| 50 ft² | 50 tiles | 55 tiles |
| 100 ft² | 100 tiles | 110 tiles |
| 150 ft² | 150 tiles | 165 tiles |
| 200 ft² | 200 tiles | 220 tiles |
| 300 ft² | 300 tiles | 330 tiles |
How Many 12 × 24 Tiles Do I Need?
A 12 in × 24 in tile covers approximately 2 ft².
A 100 ft² floor therefore requires approximately:
With 10% waste:
Why Box Coverage Matters More Than Tile Count
Tile is commonly packaged in full boxes, and different products can have different quantities of tiles per box.
For example, one 12 in × 24 in tile product might contain six tiles per box while another product might use a different quantity.
The easiest purchase calculation is therefore:
Then round upward to the next full box.
Calculate tiles and boxes in seconds
Enter tile size, room dimensions, waste and box coverage into our free Tile Calculator.
Calculate Tile NeededShould You Subtract Cabinets?
It depends on whether tile will be installed underneath them.
If permanent cabinets are already installed and you are only tiling the exposed floor, subtract the footprint of areas that will not receive tile.
If the installation plan calls for tile underneath cabinetry, include that area.
The same idea applies to kitchen islands, built-in furniture and other fixed features.
How to Calculate Tile for a Wall
Wall tile uses the same basic area formula:
If a bathroom wall measures 8 ft wide and 7 ft high:
With 10% waste:
You would plan for enough tile to cover at least 61.6 ft², then round to complete boxes.
How to Calculate Shower Tile
A shower usually contains several separate wall sections.
- Measure each wall width.
- Measure the height that will receive tile.
- Calculate each wall's area.
- Add the wall areas together.
- Subtract large openings if appropriate.
- Add the selected waste allowance.
Niches, benches, curbs and other features can add additional tiled surfaces, so include them separately.
Should You Subtract Doors and Windows?
Large openings can be subtracted when they will not receive tile.
However, openings also create extra cuts around their perimeter. For a very small opening, subtracting its exact area may not materially change the final box count.
For larger windows and doors, subtracting the area generally gives a more accurate estimate.
How Much Tile Waste for a Diagonal Layout?
Diagonal tile layouts normally create more cut pieces around walls than a straight grid.
A planning allowance around 10% to 15% may be appropriate for many diagonal layouts, although room shape and tile size can change the actual requirement.
How Much Waste for Herringbone Tile?
Herringbone patterns often require more cutting and pattern alignment than a basic straight installation.
For that reason, installers may plan for more waste than the amount used for a simple grid.
The exact allowance depends on tile dimensions, room layout and pattern orientation.
Tile Size Can Affect Waste
Small Tiles
Smaller pieces can sometimes fit around obstacles with less material loss, although mosaics may require additional sheets or pattern matching.
Large Tiles
Large-format tiles cover more area per piece but a damaged or unusable cut can represent more lost square footage.
Patterns
Layout direction and pattern often affect waste as much as the physical tile size itself.
Should You Keep Spare Tile?
Keeping a few extra tiles after installation can be useful for future repairs.
Matching replacement tile years later can be difficult because:
- The product may be discontinued.
- The color may change between production lots.
- The size or finish may be updated.
- A future replacement tile may not match exactly.
If you specifically want spare repair material, consider that separately from normal installation waste.
Why Tile Lot Numbers Matter
Tile can show slight differences in shade, texture or size between production runs.
For that reason, it can be useful to purchase all required boxes at the same time and check the lot or shade information on the packaging.
Manufacturers may also recommend mixing tiles from multiple boxes during installation to create a more natural blend.
Do Grout Joints Change the Number of Tiles?
Grout joints create spacing between tiles, but for most purchasing estimates it is still easiest to calculate the complete tiled area and use the box's stated coverage.
Published box coverage normally reflects the product's intended installation dimensions more reliably than trying to manually add grout space to every tile.
Tile Area Examples
| Room Size | Floor Area | With 10% Waste |
|---|---|---|
| 5 ft × 8 ft | 40 ft² | 44 ft² |
| 8 ft × 10 ft | 80 ft² | 88 ft² |
| 10 ft × 10 ft | 100 ft² | 110 ft² |
| 10 ft × 12 ft | 120 ft² | 132 ft² |
| 12 ft × 15 ft | 180 ft² | 198 ft² |
| 15 ft × 20 ft | 300 ft² | 330 ft² |
Common Tile Calculation Mistakes
1. Buying Only the Exact Square Footage
This leaves no allowance for broken tiles, perimeter cuts or mistakes.
2. Forgetting to Round Boxes Up
If you need 7.2 boxes, plan on purchasing 8 full boxes unless the retailer sells the product individually.
3. Ignoring the Tile Pattern
Diagonal, herringbone and other patterns can create more waste than a simple straight installation.
4. Forgetting Closets or Small Areas
Measure every area that will receive tile before adding waste.
5. Assuming All Boxes Cover the Same Area
Box coverage changes with tile size, thickness and product packaging.
6. Using Waste to Cover Unmeasured Areas
Waste should cover installation losses, not rooms or surfaces you forgot to measure.
Tile vs Flooring Waste
Tile and plank flooring use a similar estimating principle: measure the complete surface first, then add extra material for cuts and installation losses.
We explain flooring waste in more detail in:
How Much Flooring Waste Should I Add?
Frequently Asked Questions
How much extra tile should I buy?
Around 10% is commonly used for straightforward layouts. Diagonal, irregular or patterned installations may require 10% to 15% or more.
How do I calculate tile for a floor?
Multiply the floor length by width, add the selected waste percentage and divide by the coverage per tile or box.
How many 12 × 12 tiles do I need for 100 ft²?
Each 12 in × 12 in tile covers about 1 ft², so the exact area requires 100 tiles. With 10% waste, plan for about 110 tiles.
How many 12 × 24 tiles do I need for 100 ft²?
A 12 in × 24 in tile covers approximately 2 ft². The exact area needs about 50 tiles, or around 55 tiles with 10% waste.
Do I include grout lines when calculating tile?
For purchasing, use the manufacturer's stated coverage per box whenever possible. It is generally more reliable than adjusting every tile dimension manually for grout joints.
Should I buy an extra box of tile?
It can be useful when the extra quantity provides installation waste or spare matching tiles for future repairs. The right amount depends on box coverage and project size.
Should I subtract cabinets when calculating floor tile?
Subtract areas that definitely will not receive tile. If tile will be installed beneath the cabinets, include those areas.