How to use this calculator
- 1Measure the counter run: the length of wall behind the counter and hob that will be tiled. Add the runs together if the kitchen turns a corner.
- 2Set the height. A standard backsplash is 18–24 in (45–60 cm) from the counter to the wall units; choose a custom height for a feature wall up to the ceiling.
- 3Take off any area that won't be tiled — a window over the sink, or the gap behind the cooker hood.
- 4Pick the tile size and joint. Subway tiles of 3 × 6 in (75 × 150 mm) with a 1/16 in (2 mm) joint are the classic choice; mosaics on mesh sheets count by area per box.
- 5Enter the tiles per box (or the area per box) and prices to see boxes and cost.
The formula
- 01Tiled area = counter run × backsplash height − windows − area not tiled
- 02Tiles = tiled area ÷ ((tile L + joint) × (tile W + joint)) × (1 + spare %), rounded up
- 03Boxes = tiles ÷ tiles per box, rounded up (or by the area printed on the box)
- 04Adhesive ≈ area × rate for the tile size × 1.1 · Grout ≈ joint volume × 1.6 kg/L × 1.1
A backsplash is a walls-only job: the calculator takes your counter run as the wall length and the splashback height, and counts tiles on the net area after windows and gaps.
Small tiles mean many cuts at the ends of each run and around sockets, so 10 % spare is the sensible minimum; patterns like herringbone need more.
The adhesive and grout are rough figures from the same rules as our tile adhesive and grout calculators — small tiles with many joints take noticeably more grout per square metre than large ones.
Worked example
For a counter run of 10 ft with a backsplash 2 ft high, the tiled area is 20 ft².
With 3 in × 6 in subway tiles and a 0.0625 in joint, that comes to 171 tiles including spare — 4 boxes of 44.
Add about 14 lb of tile adhesive (1 bags of 50 lb) and 1.8 lb of grout.
Tips before you buy
- Lay out a dry row first: shifting the start point by half a tile can save a sliver cut at the visible end of the counter.
- Buy all the boxes from one batch — subway tiles vary slightly in shade between batches.
- Mark the socket and switch positions before tiling and cut those tiles first; a cracked cut near a socket is the most common waste.
- Use a flexible, mould-resistant grout behind the hob and sink, and silicone (not grout) in the joint where the tiles meet the counter.
- Thinking about the look first? Try the tile visualizer to see sizes and colours on a wall before you buy.
Frequently asked questions
How many tiles do I need for a kitchen backsplash?
Measure the counter run and the height, and the calculator counts the tiles on that area with your joint and 10 % spare, then turns them into boxes. For a typical 10 ft run at 2 ft high, with 3 × 6 in subway tiles, it shows the exact count above.
How high should a backsplash be?
The standard is 18–24 in (45–60 cm) — counter to wall units. Behind a hob many kitchens tile to the cooker hood, and a feature wall can go to the ceiling: pick a height or type your own.
What size are subway tiles?
The classic subway tile is 3 × 6 in (75 × 150 mm). Larger versions (4 × 12 in, 100 × 300 mm) cover faster with fewer joints. Pick a size in the calculator or type any size, including mosaic sheets by area per box.
Do I subtract the window over the sink?
Yes — set the window count and size, or put the opening into “area not tiled”, and it is taken off before the tiles are counted.
How much adhesive and grout does a backsplash need?
The results show a first estimate for your area. Small tiles have many joints, so a backsplash takes more grout per square metre than a floor; a single bag of adhesive covers most backsplashes. Use the tile adhesive and grout calculators for exact figures.
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Sources
- Tile counts: the same method as our tile calculator (tile + joint footprint, 10 % spare) — see its page for the formula and tests.
- Backsplash heights: 18–24 in counter-to-cabinet is the common rule in US and UK kitchen fitting guides; feature walls run to the ceiling.
- Adhesive rates by trowel notch: LATICRETE 254 Platinum data sheet
Formulas last reviewed: September 30, 2026 ·How we check our formulas