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How many tiles for a kitchen backsplash? (subway, 4x12, mosaic)

A backsplash along 10 ft of counter at the usual 18 inches high is 15 sq ft, which takes 128 subway tiles (3 x 6 in) with 10% cutting waste, or 48 tiles of 4 x 12, or 17 mosaic sheets. A 15 ft counter is 22.5 sq ft and 192 subway tiles; with the taller section behind a range hood it becomes 28.8 sq ft and 246. The tables cover 8 to 30 ft of counter, four tile formats, boxes, and metric splashbacks.

Open the tile calculator

Tiles by counter length, 18 inches high

Counts include 10% cutting waste. Subway tile uses a 1/16 inch joint, the 4 x 12 and 4 x 16 a 1/8 inch joint; mosaic sheets are 12 x 12 in with the joints built in.

Straight run, 18 in high, 10% waste
CounterArea (sq ft)3 x 6 in subway4 x 12 in4 x 16 in12 x 12 in mosaic sheet
8 ft12103392914
10 ft15128483617
12 ft18154584320
15 ft22.5192725425
20 ft30256967233
25 ft37.53201199042
30 ft4538414310850

With a range hood section

Where the tile runs up behind the hood, add a 30 x 30 in panel (6.3 sq ft). Taller hoods or a full-height wall behind the range: measure the panel and add it in the calculator.

Straight run plus hood panel, 10% waste
CounterArea (sq ft)3 x 6 in subway4 x 12 in4 x 16 in12 x 12 in mosaic sheet
8 ft18.3156584421
10 ft21.3182685124
12 ft24.3207775827
15 ft28.8246926932
20 ft36.33101158740
25 ft43.837413910549
30 ft51.343816312357

Boxes to order

Tiles per box differ by brand; these are common counts for about 10 sq ft a box. Round up and keep a few tiles for the day a pan hits the wall.

Boxes, straight run, 10% waste
Counter3 x 6 in subway (80/box)4 x 12 in (30/box)4 x 16 in (24/box)12 x 12 in mosaic sheet (10/box)
8 ft2222
10 ft2222
12 ft2222
15 ft3333
20 ft4434
25 ft4445
30 ft5555

How the numbers are worked out

Counter length x 18 inches gives the area; each tile plus its joint on two sides is one cell, and area divided by the cell is the count. A 3 x 6 subway tile with a 1/16 inch joint is a cell of 3.0625 x 6.0625 in, so 7.76 tiles per square foot before waste. The tile calculator takes any tile size, joint and box count; the 12x12 tile guide and the shower guide cover floors and wet walls.

Measuring the wall

  • Measure along the counter, including the short return walls at each end; do not subtract outlets and switches, the cut pieces are waste anyway.
  • Subtract a window only if it takes more than a square foot out of the 18 inch band; most kitchen windows sit above the band.
  • If the tile will run to the ceiling on one wall, measure that wall separately and add it as a second area in the calculator.
  • Buy the trim (bullnose or pencil) by the linear foot: the top edge plus any exposed end, about the counter length for a standard run.

Metric: 600 mm splashback

Tiles with 10% waste for a 600 mm high splashback, 2 mm joints; mosaic sheets 300 x 300 mm.

600 mm high, 10% waste
Worktop runArea (m²)100 x 200 mm100 x 300 mm300 x 300 mm mosaic sheet
2 m1.2654315
3 m1.8976522
4 m2.41298630
5 m316110837
6 m3.619312944
8 m4.825717259

Frequently asked questions

How many subway tiles for a backsplash?
About 7.8 tiles of 3 x 6 in per square foot with a 1/16 inch joint. A 10 ft counter at 18 inches (15 sq ft) is 117 tiles before waste and 128 with 10%; a 20 ft counter is 256. Subway tile is sold in boxes of about 80 (10 sq ft), so that is 2 and 4 boxes.
How many square feet is a typical kitchen backsplash?
Counter length in feet x 1.5 (18 inches), plus about 6.3 sq ft if the tile runs up behind a range hood. A 10 ft galley is 15 sq ft, an L-shaped 15 ft kitchen 22.5, and a 20 ft kitchen with a hood 36.3. Most kitchens land between 25 and 45 sq ft; if yours is over 60, check whether you counted the windows.
How many boxes of tile for a backsplash?
Divide the tile count with waste by the tiles per box, round up. Boxes vary by brand, so this page uses 80 subway tiles, 30 of the 4 x 12 and 10 mosaic sheets per box, about 10 sq ft each. The 15 ft counter is 3 boxes of subway or 3 of mosaic; check the count on your box and enter it in the calculator.
How much waste should I add for a backsplash?
10% for a straight run with a simple pattern; 15% for a herringbone or diagonal layout, a lot of outlets, or a hood section with cuts on both sides. Backsplash cuts are small and many, and a box short is a second trip with a different dye lot, so round up to whole boxes and keep the leftovers for repairs.
How many 4x12 tiles do I need for a backsplash?
48 for a 10 ft counter and 96 for 20 ft, at 18 inches high with a 1/8 inch joint and 10% waste. The 4 x 16 format is 36 and 72. Bigger tiles mean fewer joints and less grout, but every cut around an outlet shows more.
How many mosaic sheets for a backsplash?
One 12 x 12 in sheet covers a square foot, so sheets equal the area plus waste: 17 for a 10 ft counter, 25 for 15 ft and 40 for 20 ft with a hood section. Sheets are cut with snips between the chips, so the waste is real but small; 10% is enough.

Last updated 2026-09-13. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.