Room dimensions
Tile size (inches)
Lay pattern
Standard grid pattern. Least waste, easiest to install.
Tiles per box
Check the box at the store — this varies by tile size and brand.
Frequently Asked Questions About Tile
How many tiles do I need for my room?
To find how many tiles you need, measure the room’s length and width in feet, multiply them to get the square footage, then divide by the square footage of one tile (or one box). For example, a 10 ft x 12 ft floor is 120 square feet; if each box covers 10 square feet, you need 12 boxes. Always add 10% extra for cuts and breakage, and 15 to 20% if you’re laying tile on a diagonal or in a pattern. Our Tile Calculator handles the math and the waste factor automatically.
How much extra tile should I buy for waste?
Buy 10% extra tile for a standard straight or grid layout, which covers normal cuts around the edges and the occasional cracked tile. Increase that to 15% for diagonal layouts and 20% for complex patterns like herringbone, or for rooms with many angles, alcoves, or obstacles. It’s also smart to keep a few spare tiles after the job for future repairs, since dye lots change and an exact match may be impossible later. Buying from the same lot at once guarantees consistent color and size.
What tools do I need to install tile?
A basic tile job needs a notched trowel for spreading thinset, tile spacers for even joints, a rubber grout float, a sponge and buckets for cleanup, and a level. For cutting, a manual snap cutter handles straight cuts in ceramic, while a wet saw is better for porcelain, stone, and intricate or large-format cuts. Tile nippers shape small curves, and a tile file smooths edges. For larger format tiles, a leveling clip system helps prevent lippage (uneven tile edges).
What size tile spacers should I use?
Spacer size depends on the look and the tile: 1/16 inch gives a very tight, modern grout line common with rectified tiles; 1/8 inch is the most popular all-purpose size for wall and floor tile; and 3/16 to 1/4 inch suits larger format tiles, natural stone, and floors where slight size variation needs hiding. Larger tiles and uneven tiles generally need wider joints. Wider grout lines also use more grout, so confirm your spacing before estimating grout quantity.
Do I need backer board before tiling?
For floors and wet areas like showers and tub surrounds, cement backer board (or an equivalent tile substrate) gives a stable, moisture-resistant base that won’t flex or rot, which is essential for keeping tile and grout from cracking. Tiling directly over drywall is generally only acceptable for dry wall areas like a kitchen backsplash. Backer board is fastened to the subfloor or studs and its seams are taped with thinset and mesh tape before tiling. A solid, flat, stable substrate is the foundation of a long-lasting tile job.