Tile can really improve the appearance of a bathroom. However, measuring the bathroom for new tile can be difficult as a result of the bathroom fixtures, such as the countertop, toilet and bath. Accurately measuring a bathroom for tile is actually a fairly simple process, provided you use the proper method.
Measure the bathroom's width and length and record these measurements on a piece of paper. If the bathroom is an "L" shape, envision the bathroom as two separate, nonoverlapping rectangles and measure each rectangle separately.
If you are measuring for floor tile, simply measure the length and width of the room, or if it is L-shaped, then measure the lengths and widths of the two rectangles. If you are measuring for wall tile, measure each wall as its own rectangle. Measure each wall's length and then the width in this case would actually be the height to which you want the tile. For example, you may only want to run the tiles half way up the walls, so your width, or height, might be 1.2 m (4 feet). If you plan to tile the whole wall, your width, or height, might be 2.55 m (8 feet 6 inches).
Multiply the length and width measurements to get the total area of the bathroom. If you have an L-shaped bathroom, multiply the length and width of each section and add those two figures to get the total area. For wall tile, use the same formula and multiply your wall length by the width (height) to wehich you want to run the tile.
For floor tile, identify the immovable objects in the bathroom that you'll tile around, such as cabinets or the bath. The exception is the toilet or freestanding sinks; while you won't tile under the toilet or sink, you will need to cut tiles to fit around the base. For wall tiles, identify the objects that you will not need to tile behind, such as vanities and bath or shower surrounds. Do not include where the toilet touches the wall, as you will want to tile behind it.
Measure the footprint of the immovable objects: length and width. Multiply the length and width of each object to get its area.
Subtract the area for each immovable object from the total room area, as determined in Step 2. The total square footage figure reflects how much tile you will need to purchase.
Always purchase extra tile! Approximately 1/5 of the total square footage is a safe amount of extra tile. This will allow for tile cutting errors and you will have extra tile on-hand if a tile cracks in the future.