Planning a tiling project starts with one important question: how many tiles do you need? Buying too few can delay the project, while buying too many can increase costs and leave you with unnecessary material.

A tile calculator makes this process easier by using your floor measurements, tile size, grout gap, and waste allowance to estimate the number of tiles required. If you also enter the number of tiles per box and price per box, the flooring calculator can estimate the number of boxes and your total cost.

1. Enter the Area to Cover

Start by entering the length and width of the area in the correct unit, such as feet, meters, inches, centimeters, or millimeters.

For example, a floor that is 12 feet long and 10 feet wide has an area of:

• 12 × 10 = 120 square feet

If you already know the total area, you can use the total area option instead. Enter the area and select its correct unit, such as square feet, square meters, square inches, square centimeters, or square millimeters.

2. Enter the Tile Size

Next, enter the length and width of one tile and select its unit in feet, meters, inches, centimeters, or millimeters.

For example, if you are using a 12 × 12 inch tile, enter:

• Tile length: 12 inches
• Tile width: 12 inches
• Unit: Inches

Using the correct tile dimensions is important, as the calculator uses this information to estimate the number of tiles needed. If you’re deciding which tile to use, learn more about different types of tile and their common applications.

3. Add the Grout or Tile Gap

The Grout / Tile Gap section allows you to enter the space between tiles. Enter the gap and select its unit in Inches/ centimeter/ millimeter.

For example, you can enter 0.125 inches (1/8 inch) if that is the grout gap planned for your installation.

The right grout type can also depend on the width of the joint. Learn more about sanded vs. unsanded grout before choosing your grout.

The calculator also accepts negative gap values for specific calculation scenarios where the entered tile dimensions overlap.

For example:

• Gap = 5 mm → There is a 5 mm space between the tiles.
• Gap = 0 mm → The tiles touch each other. (No gap)
• Gap = -5 mm → One tile overlaps the other by 5 mm.

Note: Negative gap values are mainly useful for specific calculation scenarios and are not typical for standard tile installation.

4. Add Purchasing Details

The purchasing section is optional, but it can make your estimate more useful.

You can enter:

• Tiles per box
• Price per box

If you enter the number of tiles in each box, the calculator can estimate how many boxes you need. If you also enter the price per box, the tile installation cost calculator can provide an estimated cost for the tiles.

5. Add a Waste Percentage

Tiles may need to be cut around walls, corners, and fixtures. Some tiles may also break during installation. Adding extra tiles for waste helps cover these needs.

As a general guideline, a simple layout may use around 10% extra, while a more complex layout may require 15% to 20%. The appropriate allowance depends on the room shape, tile pattern, number of cuts, and tile type.

For example, with a 10% waste allowance, the calculator adds extra tiles to the amount required for the area.

6. Click Calculate 

After entering the required information, click Calculate.

The calculator will display the results, including the area to cover, effective tile size, tiles required, waste allowance, tiles to purchase, boxes required, and estimated cost when the relevant purchasing details are provided.

Example: Calculating Tiles for a 100-Square-Foot Floor

Suppose you have a 10 × 10-foot floor and want to install 12 × 12-inch tiles with a 1.5 mm grout gap and 10% waste.

Enter the following:

• Length: 10 feet
• Width: 10 feet
• Tile length: 12 inches
• Tile width: 12 inches
• Grout gap: 1.5 mm
• Waste: 10%

The area to cover is 100 square feet.

After you click on Calculate, the example calculator result shows:

• Area to cover: 100 sq ft
• Effective tile size: 306.3 × 306.3 mm
• Tiles required: 100
• Waste allowance: 10%
• Tiles to purchase: 109

The calculator estimates 100 tiles are required to cover the 100-square-foot area before waste is added. With a 10% waste allowance, the purchase quantity increases to 109 tiles. 

If you also enter the number of tiles in a box and the price per box, the calculator can calculate the boxes required and estimated cost.

What Does the Tile Calculator Show?

After you click Calculate, the results section provides several useful figures:

• Area to Cover: Shows the total area that needs to be tiled.
• Effective Tile Size: Shows the tile size used in the calculation while accounting for the grout or tile gap.
• Tiles Required: Shows the estimated number of tiles needed to cover the calculated area.
• Waste Allowance: Shows the waste percentage included in the estimate.
• Tiles to Purchase: Shows the estimated quantity after applying the waste allowance.
• Boxes Required: Shows the estimated number of boxes needed when tiles per box are provided.
• Estimated Cost: Calculates the estimated cost when the price per box is entered.

Calculating Tile Quantity for Different Spaces

The number of tiles you need depends on the size and shape of the space. The basic calculation is to find the total area and divide it by the area covered by one tile.

Living Rooms and Open Areas

For a rectangular living room, measure the length and width and multiply them to find the floor area.

For a large room with separate sections, calculate the area of each section separately, then add them together before entering the total. 

Kitchens

Kitchen floors often have cabinets, islands, or other areas that may not need tiles. Measure the actual area you plan to tile rather than using the entire room size.

For example, if the total kitchen floor is 120 sq ft but 20 sq ft does not need tiling:

• 120 − 20 = 100 sq ft

Enter 100 sq ft as the area to cover. Add a waste percentage to allow for cuts around cabinets, corners, and other fixed areas.

Bathrooms

Bathrooms are often smaller but may have more corners, fixtures, and areas that require tile cuts. Measure the floor length and width, or divide an irregular floor into smaller sections.

For example:

• 8 ft × 6 ft = 48 sq ft

If the bathroom has an additional section measuring 2 ft × 3 ft:

• 48 + 6 = 54 sq ft

Use 54 sq ft as the total area if both sections will be tiled. Then, add a waste allowance to account for extra tiles needed for cuts and installation.

Outdoor Spaces and Patios

For a simple rectangular patio, use the same length × width calculation.

For example:

• 20 ft × 10 ft = 200 sq ft

If the patio has different sections or an irregular shape, calculate each section separately and add them together. Outdoor areas may also require additional cuts, so include a suitable waste percentage when estimating the tiles to purchase.

Hallways and Entryways

Hallways are often long and narrow, so measure the length and width of each section.

For example:

• 18 ft × 4 ft = 72 sq ft

If the hallway connects to another area with a different size, calculate that section separately and add the areas together.

Irregular-Shaped Spaces

For an L-shaped or uneven floor, don’t try to calculate the entire space using one length and width. Instead, divide it into smaller rectangles.

For example:

• Main area: 10 × 8 ft = 80 sq ft
• Additional area: 6 × 4 ft = 24 sq ft

Total area = 80 + 24 = 104 sq ft

You can then enter 104 sq ft as the total area in the calculator.

The key is to calculate the area that you actually plan to tile. Once you have the figures, enter the area, tile size, grout gap, and waste percentage into the calculator to get a more useful estimate of the tiles you need.

Tips for Getting a Better Tile Estimate

• Measure the area carefully before entering your numbers.
• Keep the measurement units consistent and select the correct units in the calculator.
• Enter the actual tile dimensions you plan to use.
• Include the grout gap when required.
• Add a suitable waste percentage rather than ordering only the exact calculated quantity.
• Enter tiles per box when you plan to purchase tiles by the box.
• Add the price per box to estimate your material cost.
• Double-check your measurements before placing an order.

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