Tile calculator

Count tiles and boxes for a floor or wall, plus thinset and grout.

abLW
Letters on the drawing match the letters next to the inputs.
ft
ft
sq ft
in
in
sq ft
More settings
in
in
in
lb
Tiles88 pcs

Shopping list

  • Tiles88 pcs
  • Boxes6 boxes
  • Thinset mortar69 lb · 2 bags of 50 lb
  • Grout5.7 lb

How we got there

Area
80 sq ft
Area to buy
88 sq ft (incl. 10 % for cuts)

Results are estimates. Always check the coverage printed on the product and your local building code.

How it is calculated

The area is length × width (or height for walls) minus what stays untiled. Extra for cuts depends on the layout: 10 % for straight and offset, 15 % for diagonal and 20 % for herringbone. Thinset depends on the trowel notch, and grout uses the standard manufacturer formula with tile size, joint width and tile thickness.

FormulaTiles = area × (1 + extra) ÷ tile areaThinset ≈ area × 0.6–1.1 lb per sq ft by trowel notchGrout = (A + B) ÷ (A × B) × joint × thickness × density × area

Example

An 8 × 10 ft floor in 12 × 12 in tile laid straight needs 88 tiles, or 6 boxes of 15 sq ft. With a 1/4 in notch that is about 69 lb of thinset (2 bags of 50 lb) and 6 lb of grout for 1/8 in joints.

Tips from practice

  • Large tiles (12 × 24 in and up) need a 1/2 in notch and back-buttering.
  • Buy an extra box for repairs: the same shade may be gone later.
  • Check that all boxes share the same shade and caliber codes.

Questions and answers

How much extra tile should I buy?

10 % for straight layouts, 15 % for diagonal and about 20 % for herringbone or rooms with many corners.

How much thinset per square foot?

About 0.6 lb with a 1/4 in notch, 0.8 lb with 5/16 in, 0.9 lb with 3/8 in and 1.1 lb with 1/2 in.

Why so little grout?

Large tiles with narrow joints have very few joints per square foot. Mosaics with wide joints need far more.

Found a mistake in a formula? Write to [email protected]