The math, step by step
- Measure each run along the wall, in inches. A run is any stretch of wall above a counter. Include the wall behind a freestanding or slide-in range; skip the refrigerator and any full-height pantry cabinet.
- Measure the height. Counter to the underside of the upper cabinets is 18 inches in a standard kitchen. If a 4 inch stone splash is staying, the tile height is 14.
- Multiply and divide. Total run length × height ÷ 144 = square feet.
- Add the tall sections. Behind the range the tile usually runs up to the hood, 30 to 36 inches above the cooking surface instead of 18. A wall with a window and no upper cabinets is often tiled to the ceiling or to the top of the window trim. Measure each as its own rectangle and add only the part above the standard height.
- Subtract almost nothing. Do not subtract outlets or switches; every one is a cut tile, not a saved one. Subtract a window only if it takes more than about 4 square feet out of the tiled area.
- Add waste, then round up to full boxes. The percentage depends on the pattern; the table is below.
Worked example: an L-shaped kitchen
| Step | Numbers | Result |
|---|---|---|
| Run A (sink wall) | 120 inches | |
| Run B (range wall) | 96 inches | |
| Standard-height area | (120 + 96) × 18 = 3,888 square inches ÷ 144 | 27.0 sq ft |
| Extra behind the range, up to the hood | 30 inches wide × 12 more inches = 360 square inches ÷ 144 | 2.5 sq ft |
| Net area | 27.0 + 2.5 | 29.5 sq ft |
| Straight or running-bond pattern, 10% waste | 29.5 × 1.10 | 32.5 sq ft |
| Herringbone, 15% waste | 29.5 × 1.15 | 33.9 sq ft |
| Boxes, if one box covers 10 sq ft | Round up | 4 boxes (40 sq ft) |
Four boxes leaves six to seven square feet beyond the waste allowance in either pattern. Keep it. A backsplash tile that cracks in year three, or a new outlet added later, is repaired from that box, and the same tile bought again later will not match. The room-by-room version of this arithmetic, floors and walls included, is in how to measure a room.
Waste by pattern and tile type
| Layout or tile | Waste to add | Why |
|---|---|---|
| Straight stack or running bond (classic subway) | 10% | Cuts at the ends of each row and around outlets; offcuts often start the next row |
| Mosaic on mesh sheets | 10% | Sheets cut with a knife between tiles; little is lost, but order whole sheets |
| Diagonal | 15% | Every tile at every edge is cut to a triangle |
| Herringbone or chevron | 15 to 20% | Angled cuts at all four edges, and the offcuts rarely fit anywhere else |
| Large format (12 × 24 and up) | 15% | One bad cut around an outlet costs a whole tile |
| Handmade, zellige, natural stone | 15 to 20% | Breakage in the box, and pieces you will set aside for color or chips |
On a small job the percentages matter less than the rounding. A backsplash is 3 to 5 boxes, so the real question is whether the last box is nearly full or nearly empty. If the math lands within two square feet of a full-box total, buy one more box; running short by six tiles stops the job, and the reorder comes from a different lot.
One order, one lot. Tile is fired in batches, and shade and size drift a little between them. Order the whole backsplash at once and check that the lot or shade number printed on every box matches before the first tile is set. A backsplash sits at eye level under cabinet lights, which is the least forgiving place in the house for a shade change. The same rule, with the reasons, is in how much tile for a shower.
What else goes on the order
| Item | How much | Note |
|---|---|---|
| Edge trim (bullnose tile or a metal edge profile) | Linear feet of every exposed edge, plus one extra piece | Ends of runs that do not die into a wall or a cabinet, and the top edge wherever there is no upper cabinet |
| Adhesive | One gallon of premixed tile adhesive or a 25 lb bag of thinset covers a typical backsplash | Thinset for glass, stone and anything behind a range; follow the tile maker's sheet |
| Grout | One 10 lb bag, or one quart of premixed | Unsanded for joints under 1/8 inch and for glass or polished stone that scratches; sanded above that |
| Caulk, color-matched to the grout | One tube | The joint where the tile meets the countertop is caulked, never grouted; the two surfaces move differently and grout there cracks |
| Sealer | One pint | Natural stone and unglazed tile, and cement grout; not needed on glazed ceramic with epoxy or premixed grout |
| Outlet box extenders | One per outlet and switch in the tiled area | Tile makes the wall thicker; the extender brings the device forward so the cover plate sits flat on the tile |
| Spacers | One bag | Many subway tiles have built-in lugs; check before buying |
When to choose it, order it and install it
The backsplash is the last surface in the kitchen and it sits directly on the countertop, so the install waits for the stone. The order does not have to.
| Step | When | Why then |
|---|---|---|
| Choose the tile | With the countertop, holding a sample of each against a cabinet door | The three surfaces touch; choosing tile alone is how a white ends up looking yellow next to the quartz |
| Measure for the order | From the cabinet layout drawing, as soon as it is final | Run lengths and the 18 inch height are already fixed on paper; the waste allowance covers the small differences |
| Order special-order or handmade tile | 4 to 8 weeks before the install date | It ships from a distributor or is made to order; this is the one that catches people |
| Order in-stock tile | 2 to 3 weeks before | Time to open every box, check the lot numbers and return a damaged one |
| Confirm the measurement | The day the countertop is installed | The true height is counter surface to cabinet; a thicker top or a leftover stone splash changes it |
| Install | At least 24 hours after the countertop is set, before the outlet covers and the range go in | The top has to be in its final position; tile set first leaves a gap or gets broken when the slab slides in |
The install itself is two short days: tile set on day one, grout on day two, then caulk at the counter and sealer if the tile needs it. It fits inside the last week of the kitchen, after the stone and around the plumber's and electrician's final visits. Where that week falls, and why the countertop cannot come sooner, is in when to order a countertop; the full sequence of the room is in what order to renovate a kitchen in.
Three decisions that change the number
- Behind the range. A slide-in range has no back panel, so the wall behind it is visible down to the counter line and should be tiled. A freestanding range with a raised back hides the lower part; tile to a few inches below the top of the back panel and stop.
- The stone splash. A 4 inch strip of the countertop material along the wall is usually offered by the fabricator. With a tile backsplash, most people skip it and bring the tile down to the counter. Decide before the template visit, because it changes both orders.
- How high on open walls. Where there are no upper cabinets, the tile needs a place to stop: the underside of the hood, the top of the window trim, or the ceiling. Pick a line that already exists in the room; a backsplash that ends in mid-wall looks unfinished.
Thirty square feet of tile is the smallest order in the kitchen and the one most often placed late, because it feels like a finishing touch. Measure it from the drawings, order it with the long-lead items, and let the boxes wait in a closet. Tile keeps; an open wall behind a finished counter does not.