How do I calculate how many tiles?

Calculating the number of tiles needed for a project can seem daunting, but it’s actually quite straightforward with some simple math. Whether you’re tiling a floor, wall, or countertop, you need to measure the area to be tiled and divide by the size of your tiles to determine how many you need. In this article, we’ll walk through the step-by-step process to calculate tile quantities for any tiling project.

Measure the Area to be Tiled

The first step is to measure the surface area that will be covered in tile. This requires measuring the length and width of the space. For a rectangular room, you can simply multiply the length by the width to get the square footage. For more complex shapes, you may need to break the area into separate rectangles and triangles to get an accurate measurement. Be sure to write down the measurements for each section.

Here are some tips for getting accurate measurements:

  • Measure length in feet and round up to the nearest half foot or whole foot
  • For width, measure at several points and use the smallest measurement
  • Include any irregular nooks or crannies in the area
  • For walls, measure from the floor to the height you want to tile

Once you have all the measurements, add up the total square footage that will need tile. Having an accurate area measurement is crucial for calculating the quantity of tiles.

Determine the Size of the Tiles

Next, you need to know the dimensions of the tile you will be installing. Tile sizes are usually expressed in inches like 12×24 or 16×16. This refers to the height x width in inches. Common standard sizes include:

  • 12 x 12 inches
  • 16 x 16 inches
  • 18 x 18 inches
  • 12 x 24 inches
  • 20 x 20 inches

Tile may also come in metric sizes like 300x300mm. If you’re using metric tiles, be sure to convert the dimensions to inches before calculating. You can find the tile dimensions printed on the box or on the retailer’s product description online.

Calculate the Square Inches per Tile

To determine how many tiles are needed, you first need to calculate the square inch coverage of each individual tile. This is done by multiplying the height x width dimensions in inches. For example:

  • 12 x 12 inch tile = 144 square inches
  • 16 x 16 inch tile = 256 square inches
  • 12 x 24 inch tile = 288 square inches

Make a note of the total square inches for the size of tile you’ll be installing. This number will be used in the final calculation.

Divide Total Area by Tile Square Inches

Now for the final step – dividing the total area in square feet by the square inch coverage per tile. This will tell you how many tiles are required to cover the area.

Here’s the formula:

Total area (square feet) ÷ Tile size (square inches) = Number of tiles needed

Let’s break this down in an example:

  • Total area: 150 square feet
  • Tile size: 16 x 16 inches = 256 square inches

Using the formula:

150 square feet ÷ 256 square inches = 586 tiles

So for a 150 sq ft area using 16-inch square tiles, you would need 586 tiles total. Make sure to round up to account for cutting waste and any irregular edges.

Calculate Other Materials Needed

Now that you know how many tiles are required, you can also estimate the quantity of grout and adhesive you’ll need. Typically you’ll need about 25 lbs of thinset mortar and 1 lb of grout per 10 sq ft. For our 150 sq ft example:

  • Thinset mortar: 150 sq ft ÷ 10 = 15 buckets at 25 lbs each, so 375 lbs
  • Grout: 150 sq ft ÷ 10 = 15 lbs needed

For large jobs, make sure you have 10-20% extra tile on hand for cuts, waste, and breakage. It’s better to have too many tiles than not enough!

Consider a Tile Layout Plan

When purchasing tile, also think about the layout pattern and where you want the tile seams and cuts. Natural stopping points like walls and cabinets are ideal. Making a basic layout or grid plan will ensure you purchase the right quantities for your design.

Here are some common tile layout patterns:

  • Brick pattern: Tiles offset by 50% for each alternating row
  • Subway tile: Staggered brick pattern with grout lines aligned
  • Herringbone: Tiles form a V pattern
  • Hexagonal: Honeycomb pattern with tiles fitting together in grids

Having a layout planned will also inform you on how many full tiles are needed versus cuts.

Cutting Tile

Most tile projects will involve some cutting around edges and obstacles. Here are some tips for cutting tile:

  • Use a wet saw for straight cuts and a tile cutter for small notches
  • Cut tile face up for ceramic and porcelain, face down for natural stone
  • Start by scoring the tile then snap it along the line
  • For round openings, use a tile bit on a drill or an oscillating multi-tool
  • Use a diamond blade and slow steady pressure when cutting
  • Always wear safety goggles when cutting tile

Having extra tile on hand allows you flexibility for any required cuts. It’s generally a good idea to add 10% more tiles to your calculated quantities.


Calculating the number of tiles for a project requires just a few simple steps:

  1. Accurately measure the area to be tiled
  2. Determine the tile dimensions
  3. Calculate the square inches per tile
  4. Divide the total area by the tile square inches

Be sure to add extra for cutting waste and breakage. Measuring carefully, having some layout plans, and using the tile calculations formula will help ensure you get the perfect quantity of tile for your next project.

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