Tile Calculator
Enter your room area, tile size, and grout line width to estimate how many tiles to buy, with a waste allowance built in.
Last updated: September 5, 2026
Frequently asked questions
How many 12x12 tiles do I need for 100 sq ft?
With a 1/8 inch grout line and 10% waste allowance, 100 sq ft needs about 108 tiles.
Why does grout line width affect tile count?
Grout lines add space between tiles, slightly increasing each tile's effective footprint - over a large room this adds up to a few extra tiles beyond a simple area ÷ tile size calculation.
Should I buy extra tile beyond the waste allowance for future repairs?
It's a common practice to keep a few extra tiles from the same production batch/dye lot specifically for future repairs, since tile colors can vary slightly between manufacturing batches and an exact match may not be available later.
Does tile size affect how much waste allowance I should use?
Yes - larger tiles generally need a lower waste percentage since fewer cuts are required for the same area, while smaller tiles, mosaics, or diagonal layouts need a higher waste allowance because more pieces get cut and discarded around edges.
How many 6×6 tiles do I need for a 10×12 ft bathroom?
10×12 ft is 120 sq ft. With a 1/8 inch grout line, each tile covers about 0.26 sq ft (6.125×6.125÷144). With a 10% waste allowance, 120 sq ft needs about 132 sq ft of coverage, which comes out to roughly 507 tiles.
Should I round the tile count up or use the decimal number the calculator gives?
Always round up to the next whole tile - partial tiles aren't sold, and the waste allowance already accounts for the extra cut pieces this rounding produces plus additional cuts made on-site.
Should I use the tile calculator or the flooring calculator for a tiled floor?
Use this tile calculator when you know your exact tile dimensions and grout line width, since it accounts for grout spacing between individual pieces. The general flooring calculator is better suited to plank or box-based flooring that's priced and sold per box of a known square footage.