BuildEstimate

How many 12x12 tiles for 100 square feet? (12x24, 18x18, 24x24 too)

A 12 x 12 inch tile with a 1/8 inch grout line covers a little more than one square foot, so 100 square feet takes 98 tiles exactly and 108 once you add 10% for cuts and breakages; laid diagonally, 113. Larger formats need fewer pieces: 55 of the 12 x 24 inch size for the same floor. The tables cover 100 to 500 square feet in the common sizes and turn tiles into boxes.

Open the tile calculator

Tiles for 100, 200, 300 and 500 square feet

Each count includes a 1/8 inch grout line around every tile and 10% waste, then rounds up to a whole tile. The second column is the exact number per 100 square feet before waste, useful for checking a quote.

Tiles to buy, 1/8 in grout, 10% waste
Tile sizePer 100 sq ft (exact)100 sq ft200 sq ft300 sq ft500 sq ft
12 x 12 in97.9108216324539
12 x 24 in49.255109163271
18 x 18 in43.84997145242
24 x 24 in24.7285582137
6 x 24 in97.5108215322536
4 x 12 in287.93176349511,584

How the numbers are worked out

One tile plus its share of grout is a cell of (12 + 1/8) x (12 + 1/8) inches, or 1.021 square feet. Divide the floor area by the cell, multiply by 1.10 for waste, round up. The tile calculator does this for any tile size, grout width and waste, and gives boxes if you tell it the count on the box.

From tiles to boxes

Boxes of 12 x 12 tile hold anywhere from 8 to 15 pieces depending on thickness and brand, so there is no single answer; find the count or the square feet printed on the box and use the matching row.

Boxes of 12 x 12 in tile, 10% waste included
Tiles per box100 sq ft200 sq ft300 sq ft
8 per box142741
10 per box112233
12 per box91827
15 per box81522

Waste: straight, diagonal, patterned

Waste is the tile you cut off at the walls and around fixtures plus the odd broken piece. A straight grid in a rectangular room loses about 5 to 10%; a diagonal layout cuts every tile along two walls and loses 15% or more; herringbone and other patterns with large offsets can reach 20%. Rooms with alcoves, islands and lots of pipes sit at the top of each range. The 15% diagonal figure for 100 square feet of 12 x 12 is 113 tiles.

Large format: 18x18 and 24x24

Bigger tiles mean fewer pieces and fewer grout lines, but each cut wastes more, and the floor underneath must be flatter: a 24 x 24 tile shows any hump as lippage. Rectified large-format tiles are often laid with a 1/16 inch line, which changes the count by less than 1%.

Before you order

  • Measure the room at floor level, in feet and inches, and multiply length by width. For an L-shaped room add two rectangles; the room planner gives the floor area of any outline.
  • Order everything from one dye lot and check the lot number on each box when it arrives.
  • Thinset and grout are separate: bags are labelled by the square feet they cover for a given tile size and trowel notch.
  • Metric sizes (30 x 30, 60 x 60 cm)? See tiles per square metre.

Frequently asked questions

How many 12x12 tiles do I need for 100 square feet?
98 tiles cover 100 square feet with a 1/8 inch grout line; buy 108 to allow 10% for cutting and breakage, or 113 for a diagonal layout. A 12 x 12 tile is not quite a square foot once the grout is added, which is why the count is slightly under 100 before waste.
How many 12x24 tiles for 100 square feet?
50 exactly and 55 with 10% waste. Plank and rectangular tiles are usually laid in an offset pattern, which cuts one tile per row at each wall, so keep the full 10% even on a simple room.
How many boxes of tile do I need?
Divide the tiles with waste by the number printed on the box and round up. For 100 square feet of 12 x 12 tile that is 11 boxes of 10 or 8 boxes of 15. Boxes are often labelled by square feet instead; then divide the area plus waste by that figure.
How much extra tile should I buy for waste?
10% for a straight layout in a simple room, 15% for diagonal or herringbone patterns and rooms with many corners, and 20% for natural stone or a large-format tile that chips easily. Keep a few spare tiles from the same batch for future repairs; dye lots change.
Does the grout line change how many tiles I need?
Slightly. With a 1/16 inch line a 12 x 12 tile covers less area than with 1/8 inch, so you need about 1% more tiles; with 3/16 inch about 1% fewer. It matters more on small tiles: the tile calculator lets you set the grout width for any size.
How many tiles per square foot?
0.98 of the 12 x 12 size, 0.97 of 6 x 24 planks and 2.88 of 4 x 12 subway tiles, all with a 1/8 inch grout line and before waste.

Last updated 2026-09-12. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.