Bathroom Tile Planning: Floors, Walls and Boxes

Plan bathroom floor tile and wall tile as separate purchases. They may have different sizes, package coverage, installation patterns and suitability requirements. This guide turns one measured room into a clear box estimate; use the tile calculator for your actual product.

Measure the floor first

For a rectangular 5 × 8 ft bathroom, floor area is 40 sq ft. Add closets or alcoves that will be tiled, and subtract only areas that will remain untiled. A fixed cabinet footprint should be excluded only when the installation plan calls for no tile beneath it. Use the L-shaped room calculator when the floor has a right-angled extension.

Measure each wall to its actual tiled height

If all four walls in the example are tiled to 8 ft high, perimeter is 2 × (5 + 8) = 26 ft and gross wall area is 26 × 8 = 208 sq ft. A 3 × 7 ft door subtracts 21 sq ft, leaving 187 sq ft of wall tile area. Subtract other untiled openings that are actually in the tiled zone.

For half-height tiling, a shower enclosure or walls with different heights, list each wall separately as width × tiled height and sum the results. Do not multiply the whole perimeter by the tallest wall. Measure window returns, niches, ledges and the shower curb separately if they need tile.

A complete box example

Suppose the floor tile is sold in boxes covering 10 sq ft and the wall tile in boxes covering 13.5 sq ft. With an illustrative 10% allowance, the floor needs 44 sq ft: 44 ÷ 10 = 4.4, so buy 5 boxes covering 50 sq ft. The walls need 205.7 sq ft: 205.7 ÷ 13.5 = 15.237…, so buy 16 boxes covering 216 sq ft. These are separate products and cannot be combined into one box count.

If that wall product contains six nominal 18 × 18 in tiles, each tile face is 2.25 sq ft and the area estimate is 92 tiles after rounding up. Six tiles per box means 16 boxes supply 96 tiles. Verify the actual carton coverage: tile face arithmetic is an estimate and does not model grout joints, trims or a detailed cutting layout.

Keep allowance and box rounding visible

Extra tile depends on pattern, breakage, obstacles, tile size and the installer’s cut plan. Ten percent illustrates the arithmetic; diagonal layouts or intricate cuts may require a different allowance. Round whole boxes only after applying the chosen allowance, and keep an appropriate matching spare supply if the product instructions or installer recommend it.

Build a purchase checklist

• Floor tile: net area, chosen allowance, carton coverage and whole-box total.
• Wall tile: each tiled wall, openings, returns and separate product totals.
• Edge trims and transitions: measure linear feet rather than square feet.
• Adhesive and grout: use the manufacturer’s coverage for the tile, trowel, substrate and joint size.
• Wet areas: follow the complete waterproofing system instructions and confirm tile suitability for its location. Tile area alone does not specify waterproofing.

Common measuring mistakes

Do not subtract an opening twice, use floor area as wall area, mix feet with inches, or reuse adjusted area and add the same allowance again. A bathroom material estimate also excludes labor and delivery unless you enter those costs explicitly.

Calculate your quantities

Estimate floor or wall tile boxes · Estimate the flooring material budget · Measure an L-shaped floor

Reviewed October 5, 2026. Measurements and examples are for planning; product specifications and the actual installation layout control the order. See our calculation methods and product sources.