Step 1: Measure the area to be covered.

Convert all measurements to feet using the appropriate conversion factors.

Calculate total area: $$\text{Total Area} = \text{Length (ft)} \times \text{Width (ft)}$$

Step 2: Measure the tile area including spacing.

Calculate tile area with spacing: $$\text{Tile Area with Spacing} = (\text{Tile Length (ft)} + \text{Tile Spacing (ft)}) \times (\text{Tile Width (ft)} + \text{Tile Spacing (ft)})$$

Step 3: Estimate the number of tiles needed.

Calculate total number of tiles: $$\text{Tiles Needed} = \frac{\text{Total Area}}{\text{Tile Area with Spacing}} \times (1 + \text{Waste Factor})$$

Step 4: Calculate the total cost (if price per tile is provided).

Formula: $$\text{Total Cost} = \text{Tiles Needed} \times \text{Price per Tile}$$

Tile Size in Inches	Tile Size in Centimeters	Tiles per 100 ft²
4″ x 4″	10 cm x 10 cm	900
3″ x 6″	7.5 cm x 15 cm	800
6″ x 6″	15 cm x 15 cm	400
4″ x 24″	10 cm x 61 cm	150
12″ x 12″	30 cm x 30 cm	100
16″ x 16″	41 cm x 41 cm	57
18″ x 18″	46 cm x 46 cm	45
18″ x 24″	46 cm x 61 cm	34

Installing kitchen and bathroom tiles often involves creating patterns using various tile sizes. To approximate the number of tiles needed, follow these steps:

1. Calculate the square footage of the repeating pattern.
2. Determine how many such patterns are required for the area.
3. Multiply by the number of tiles necessary to complete one pattern.

For example, if your pattern calls for one 4x4 tile and two 2x4 tiles:

• Add the square footage of both tile sizes to obtain the total square footage of the pattern.
• Divide the total square footage of the floor by the square footage of the pattern to find out how many patterns fit into the space.

It's important to note that if the tiles are not sold as a pre-packaged pattern, you'll need to:

• Calculate the square footage for each tile size individually.
• Order the required amounts.
• Arrange them according to the pattern.

In the case of the aforementioned tile sizes, you might need equal quantities of both tile sizes. To do this:

• Divide the total square footage by two.
• Add 20% for waste.
• Order accordingly.

However, for different tile sizes and patterns, the square footage required for each tile may vary, necessitating separate calculations.

Certain patterns, such as herringbone, subway, or diagonal layouts, that use tiles of the same size may also impact the amount of material needed due to the varying number of cuts and waste generated by different installations. Some patterns inherently result in more waste than others.

As a general guideline, when installing tiles at an angle, consider ordering 20% extra material to account for additional cuts and waste.