How To Calculate Tile Quantities — Your Complete Measuring, Waste, and Ordering Guide

It's important to calculate tile quantities required before commencing any project. Use the following formula to do so: 

Length × Width + Waste = Total Tile Needed 

You can use this simple formula for any tile project, whether you're redoing the bathroom floor, putting up a kitchen backsplash, or creating a custom shower. 

Once you've determined the number of tiles needed, consider adding an extra 10–20% to account for cuts or future repairs. 

Follow the simple steps below to make sure your calculation is accurate: 

Step 1: Measure Wall or Floor Areas 

Start by preparing a tape measure, pencil, paper, and calculator because you'll need them to measure your wall or floor areas. You'll want to write down both the length and width of each wall or floor you're planning to tile, but don't forget to factor in any windows or doors that might get in the way. Measuring square and rectangular spaces is pretty simple, but if you're working with a complicated space, just break it into smaller rectangles and measure the width and length of each piece separately. 

Step 2: Multiply the Measurements To Get the Total Area 

Once you have the measurements of each area, multiply them to determine the total area you need to tile. So, if your floor is 6.6 feet wide and 9.8 feet long, you're looking at a total area of 64.7 square feet (6.6 ft × 9.8 ft = 64.7 sq. ft.). For a trickier shape, break it down into simple squares or rectangles, calculate each one, and then add them up for the total. 

The calculations above will help you find the exact area to tile, but keep in mind that measurements don't account for potential breakages and offcuts. Usually, adding about 10-20% extra is a good idea — it can help cover any unexpected accidents and give you some spare tiles for future breakages. 

To find the overage, simply multiply the total area from Step 2 by 10%. For instance, in this case, you would do 64.7 sq. ft x 1.1, which equals 71.2 sq. ft. 

Step 4: Calculate How Many Tiles Are Needed 

Check the size of the tiles you've picked and see how many are packed in a box. The number can really differ—a box of smaller subway tiles usually has way more tiles than a box of those big, fancy tiles. Once you've got that sorted, figure out how much area one tile covers. For example, a tile that's 4 in × 8 in covers 32 sq. in, or 0.22 sq. ft. 

After that, divide the total room area, including any extra for mistakes, by the area one tile covers. So, if you have 71.2 sq. ft. of space, you'd do 71.2 sq. ft. divided by 0.22 sq. ft., which gives you 324 tiles needed. Then, see how many tiles come in each box and divide the total tiles needed by the number in a box. Say you've got 20 tiles per box, so you'd calculate 324 divided by 20, ending up with 16.2 boxes. You can then round that up to 17 boxes. 

When you're out shopping, you'll find that many tile boxes will tell you how much area they cover or how many you'll need to cover 1 sq. ft.