Tile calculator

Floor or wall, any tile size, any layout. You get boxes to buy with the right waste factor, plus thinset, grout, and a cost range.

Printed on the box. Leave as-is if unsure.

Vanity, tub, island footprint.

Calculator last reviewed 2026-09-03. How we calculate.

How this calculator works

Area is length × width minus anything you're skipping. We add waste for cuts and breakage — 10% for a straight layout, 12% for offset, 15% for diagonal or herringbone, which is what most installers order. Tiles needed is that area divided by the size of one tile plus its grout joint. Boxes is tiles-with-waste divided by the square feet printed on the box, rounded up. Thinset is estimated at one 50-lb bag per 90 sq ft (¼" × ¼" trowel; large-format tile with a ½" trowel uses about twice that) and grout at roughly 1 lb per 8 sq ft for a ⅛" joint on 12×24 tile.

tiles = area × (1 + waste) ÷ ((tileW + joint) × (tileH + joint) ÷ 144)
boxes = ⌈ area × (1 + waste) ÷ sqft_per_box ⌉

Frequently asked questions

How much extra tile should I buy?

Ten percent for a straight layout, 12% for offset or brick patterns, and 15% for diagonal or herringbone. Buy it all from the same dye lot; a box bought later can be a visibly different shade. Keep a few spare tiles for future repairs.

How many 12×24 tiles are in a box?

Usually 6 to 8, covering about 12 to 16 sq ft. The number varies by manufacturer, which is why this calculator asks for the square feet printed on your box rather than assuming.

How many square feet does a bag of thinset cover?

A 50-lb bag covers roughly 80–100 sq ft with a ¼" × ¼" square-notch trowel. Large-format tile (any side over 15") needs a ½" × ½" trowel and back-buttering, which drops coverage to 40–50 sq ft per bag.

Should I tile on the diagonal?

Diagonal layouts make small rooms look larger but generate more cuts and about 5% more waste. They also take longer, so expect a higher installation quote.

Painting too? Plan the whole project.

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