Backsplash Tile Calculator
Enter the run length, the backsplash height and any openings, choose a waste factor and a unit size — this calculator returns the tiles or mosaic sheets to buy.
Calculator
A backsplash 10.0 ft long × 1.50 ft high, less 0.0 sq ft of openings, is about 15.0 sq ft; with waste, about 17 units at 1.00 sq ft each. This is a tile-quantity calc for a backsplash, not a kitchen remodel. Confirm sheet/tile coverage on the box.
Formula
The backsplash area is the wall run times the height, minus any openings; units round up after a waste factor:
area = wall_lf × height_ft − openings_sqft units = ceil( area × (1 + waste) ÷ unit_sqft )
Length and height are in feet, so their product is square feet directly. Subtract the square footage of windows, a range hood or any run you are not tiling. Then gross up by the waste factor and divide by the coverage of one unit — a single tile or a mosaic sheet (a 12 in sheet is 1 sq ft).
Worked example
Take a 10 lin ft run at the common 18 in (1.5 ft) counter-to-cabinet height, no openings, at 10% waste, using 1 sq ft mosaic sheets:
- Area: 10 × 1.5 − 0 = 15 sq ft.
- With waste: 15 × 1.10 = 16.5 sq ft.
- Sheets: 16.5 ÷ 1 = 16.5 → ceil(16.5) = 17 sheets.
So you would buy 17 mosaic sheets. Subtract a window: a 3 sq ft opening drops the area to 12 sq ft and the count to ceil(12 × 1.10) = 14 sheets.
Measuring a backsplash and picking a waste factor
A backsplash is just a small wall area, so the math is length × height minus the parts you skip. Measure the full run of countertop the backsplash follows, including the returns at the ends of an L- or U-shaped counter, and use the height from the counter to the underside of the upper cabinets — commonly 18 in (1.5 ft), though a full-height backsplash behind a range or open shelving can be 24 in or more. Subtract windows, the footprint of a range hood, and any stretch you are not tiling.
Backsplashes are cut-heavy for their size: outlets, switches, end returns and the line under the cabinets all create cuts, and mosaic sheets in particular generate offcuts you cannot always reuse. A 10% waste factor is a sensible minimum; step up to 15–20% for a diagonal set, a herringbone or a picket pattern, or a wall full of outlets. Buy a spare sheet or two beyond the calculated count and keep them for repairs, since dye lots shift between runs.
Set the unit size to match how your tile is sold: a 12 in mosaic sheet is 1 sq ft, while individual subway or field tiles have their own coverage. Confirm the coverage on the box and remember this is a tile-quantity estimate for a backsplash, not a kitchen-remodel cost and not an installation guide — for grout and setting mortar behind the tile, see the grout and thinset calculators.
Trim and accent pieces are counted separately from the field area this tool sizes. If you are finishing the exposed top edge or the outside corners with pencil liner, quarter-round or bullnose, add those by the linear foot; if you are running a decorative band or a focal panel behind the range, price that tile on its own line because it often comes at a different unit size and coverage. It also pays to think about where the layout starts: centering the pattern on the range or the sink and working outward makes the end cuts symmetrical but can leave slivers at the ends, which nudges the waste factor up. None of that changes the core area math — length times height minus openings — but it decides how many spare units you keep on hand.
Frequently asked questions
How do I measure a backsplash?
Measure the total length of countertop the backsplash runs along (in linear feet), including end returns, and the height from the counter to the underside of the upper cabinets (commonly 18 in = 1.5 ft). Multiply them for the area, then subtract the square footage of windows, hoods or any untiled stretch.
How many mosaic sheets for a 10 ft backsplash?
For a 10 ft run at 18 in high with no openings, 10% waste and 1 sq ft sheets, about 17 sheets: 10 × 1.5 = 15 sq ft, × 1.10 = 16.5, rounded up. Subtracting a 3 sq ft window drops it to about 14.
What waste factor should I use for a backsplash?
At least 10% because backsplashes are cut-heavy around outlets, ends and the cabinet line. Use 15–20% for a diagonal, herringbone or picket pattern, or a wall with many outlets and switches.
How do I handle outlets and a window?
Do not subtract small outlets and switches — the cuts around them are what the waste factor covers. Do subtract larger openings you will not tile, such as a window or the footprint of a range hood, by entering their area in the openings field.
Is a backsplash a kitchen remodel?
No — this is purely a tile-quantity calculator for the backsplash surface. It does not price cabinets, countertops or a whole-kitchen project; those belong to a remodel estimate, not to a tile-count tool.