Tile Calculator

Tiles, thinset & grout for floors & walls

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Formula & explanation

Tiles = ceil(area × (1+waste) ÷ (tileW × tileH ÷ 144))

Area is length × width in feet. Each tile's area in square feet is its width × height in inches ÷ 144 (sq inches per sq ft). Divide the waste-adjusted area by the tile area and round up. Grout-line width slightly reduces tiles needed but is usually ignored in planning.

Example calculation

10 × 12 ft floor, 12×12 in tiles, 10% waste:

Area = 120 sq ft × 1.10 = 132 sq ft. Tile area = 12×12÷144 = 1 sq ft. Tiles = 132. Thinset = 2 bags. Grout = 1 bag.

Buying & project-planning tips

  • Buy 15–20% extra for diagonal layouts or large-format tiles with lots of cuts.
  • Mix tiles from 2–3 boxes at a time to blend dye-lot color variation.
  • Use a notched trowel sized to your tile — bigger tiles need larger notches for full coverage.
  • Seal natural stone tiles before grouting to prevent staining.
  • Keep leftover tiles and grout for future repairs — dye lots change over time.

Frequently asked questions

Do I include the grout line in the calculation?+

Grout lines slightly reduce the number of tiles needed, but for planning it's safer to ignore them and rely on the waste allowance — you'll have spares either way.

How much thinset and grout do I need?+

A 50 lb bag of thinset covers roughly 75 sq ft with a 1/4" notch. A 25 lb bag of grout covers about 150 sq ft for 12" tiles with 1/4" joints — adjust for tile size and joint width.

Should I buy extra tiles?+

Yes — buy 10–20% extra depending on layout complexity, and keep leftovers. Tile patterns get discontinued and exact dye-lot matches become impossible over time.

What size trowel for large tiles?+

Use 1/4" × 3/8" notch for 12–16" tiles and 1/2" notch for tiles 16" and larger to ensure full mortar coverage.

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Estimates only — not professional advice. All results are planning estimates and do not replace evaluation by a licensed contractor, electrician, plumber, HVAC technician, or engineer, or required permits and local building code compliance. Always verify with your supplier and local authority before purchasing or starting work.

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