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Units

Backsplash Tile Calculator

Enter each counter run, the backsplash height, windows and the range, and get tiles or mosaic sheets, edge trim, grout and thinset.

Units

Counter runs

  • Run 1 length
    ft
    in
  • Run 2 length
    ft
    in
in

Counter to the bottom of the upper cabinets; 18 in is the usual gap.

Open ends that need trim

Windows, range and outlets

in
in
in
in

Their area is too small to subtract, but each needs a box extender after tiling.

Tile

in
in
%

Backsplashes are all cuts around outlets and windows: 10% is the minimum, 15% with a mosaic or a herringbone.

Tiles to buy

201tiles

3 × 6 in for 23.5 sq ft, 3 boxes, 10% extra for cuts.
Area to tile
23.5sq ft
Edge trim
17lin ft
Or bullnose pieces
38
Unsanded grout
1.2lb
Thinset, 50 lb bags
1
Box extenders
4
Run 1: 10 ftRange30 inRun 2: 6 ft18 in

Rows start with a full tile on the counter, where the eye lands; the cut row goes under the cabinets. The range area is drawn on the second run.

The math

  1. Runs × height

    10 ft + 6 ft = 16 ft, × 18 in = 24 sq ft

  2. Minus window

    36 in × 12 in = − 3 sq ft

  3. Plus range area

    30 in × (30 in − 18 in) = + 2.5 sq ft

  4. Tiles

    23.5 sq ft ÷ 0.129 sq ft per tile × 1.1, rounded up = 201 tiles

  5. Edge trim

    16 ft top edge − 30 in under the hood + 2 × 12 in range sides + 1 × 18 in open end = 17 ft

Joints under ⅛ in take unsanded grout: 1.2 lb of MAPEI Keracolor U, from its coverage chart. Thinset at 85 sq ft per bag with a ¼ × ¼ in notch (CUSTOM VersaBond).

Material list

16 ft of counter, 18 in high, 23.5 sq ft of 3 × 6 in, 10% waste

QuantityItem
201tiles

Tile, 3 × 6 in

3 boxes

17lin ft

Edge trim, or bullnose tile

or 38 bullnose pieces

1bags

Unsanded grout, 10 lb

1.2 lb

1bags

Thinset, 50 lb

¼ × ¼ in square-notch trowel

4pcs

Outlet box extenders

bring the device flush with the new tile face

A kitchen backsplash along 16 ft of counter, 18 in high, with a window cutting 12 in into it and tile run up to the hood behind a 30 in range, is 23.5 sq ft: 201 subway tiles of 3 × 6 in at 1/16 in joints, with 10% extra. Measure each counter run, multiply by the height, take out the windows and add the tall area behind the range.

How the backsplash tile is calculated

The backsplash is a strip: the total length of the counter runs times the height from counter to cabinets. Windows that dip into the strip come off (their width times how far they reach down into it). Behind the range the tile usually continues up to the hood, which adds the range width times the extra height.

area = total run × height − window width × reach + range width × (tile height at range − height)

tiles = area ÷ ((tile width + joint) × (tile length + joint)) × (1 + waste %), rounded up

Outlets and switches are not subtracted: a 2 × 4 in box is less than a tenth of a square foot and the tile around it is cut, not saved.

Worked example

These are the calculator's defaults: an L-shaped counter with runs of 10 and 6 ft, 18 in to the cabinets, a 36 in window reaching 12 in into the backsplash, a 30 in range tiled to 30 in, one open end.

  • Strip: 16 ft × 1.5 ft = 24 sq ft.
  • Window: 3 ft × 1 ft = 3 sq ft off.
  • Range: 2.5 ft × (30 − 18) in = 2.5 sq ft on.
  • Net: 23.5 sq ft.
  • 3 × 6 in subway at 1/16 in joints: each tile with its joint covers 3.0625 × 6.0625 = 18.57 sq in, so 23.5 × 144 ÷ 18.57 = 182.3, × 1.10 = 201 tiles.
  • Edge trim: 16 ft of top edge, minus the 2.5 ft that disappears under the hood, plus 2 × 1 ft up the sides of the range area, plus 1.5 ft on the open end = 17 linear ft, or 38 bullnose pieces 6 in long with 10% extra.
  • Grout: 1.2 lb of unsanded grout, so one small bag. Thinset: one 50 lb bag with a ¼ × ¼ in notch, with most of it left over.

Subway tile or mosaic sheets

Mosaics are sold in sheets that cover close to one square foot each; the same 23.5 sq ft takes 26 sheets of 12 × 12 in with 10% extra. Pick the mosaic sheet as the tile size and the calculator counts sheets and works the grout out on the small chips, which need several times more grout per square foot than subway tile. Sheets are easy to cut along a grout line around outlets, and the layout preview draws the chip grid so you can see where the cuts land.

For subway tile, the rows start with a full tile on the counter, where the eye lands, and the cut row goes under the cabinets. With 3 in tile at 1/16 in joints, 18 in of height gives five whole rows and a cut row of about 2 ¾ in under the cabinets; if your height leaves a sliver instead, start the first row with a cut piece or adjust the joint.

Edge trim and bullnose

Wherever the tile ends in the open, not against a cabinet, wall or counter, the raw edge needs finishing: bullnose tile (a matching piece with one rounded edge) or a metal or PVC edge profile. The calculator counts the top edge, the open ends and the sides of the tall range area. It leaves out the edges that die into a wall corner or a cabinet side.

Grout, joints and mortar

At 1/16 in, subway joints are too narrow for sanded grout: MAPEI says its sanded Keracolor S is not for joints under ⅛ in, so the calculator switches to an unsanded grout and uses Keracolor U's coverage. ANSI A108.02 sets 1/16 in as the narrowest joint allowed at all. For the mortar, CUSTOM's trowel guide gives a ¼ × ¼ in square notch for tile 8 in or smaller; for the brand coverage, the grout calculator and the thinset calculator show the data sheet figures.

Before and after

Tile goes on after the counter is set, so measure from the finished counter. If the counter is still to come, the countertop calculator sizes the slab. Leave the joint between counter and tile open and seal it with silicone; the caulk calculator counts the tubes. For a full kitchen budget, the kitchen remodel cost calculator has the numbers, and for floors or walls elsewhere in the house, use the tile calculator.