Backsplash Calculator
Work out exactly how many tiles, how much adhesive and how much grout a backsplash needs, with the right waste allowance for your layout already built in. Add your own prices for a full cost estimate — nothing here uses a stale national average.
How this calculator works
This uses the same footprint-and-waste logic as a floor or wall tile job, just applied to a narrow strip: each counter run's length times the backsplash height gives its area, openings come off that total, and each tile's real footprint includes half the grout gap on every side:
area = sum(run_length × height) − sum(subtracted areas) tile_footprint = (tile_width + gap) × (tile_height + gap) tiles = ceil(area / tile_footprint × (1 + wastage%))
Adhesive and grout are calculated from the net installed area, not the waste-adjusted figure, since they only cover the wall that's actually there — the waste allowance is specifically for tiles lost to cuts.
Worked example
An 8 ft and a 5 ft counter run, 18 in backsplash height, minus a 2.5 ft × 1.5 ft window, in 3×6 in subway tile with a 1/16 in grout gap, straight lay:
- Gross area: (8 + 5) × 1.5 ft = 19.5 sq ft.
- Window: 2.5 × 1.5 = 3.75 sq ft subtracted.
- Net area: 19.5 − 3.75 = 15.75 sq ft.
- Tile footprint: (3 + 0.0625)/12 × (6 + 0.0625)/12 ≈ 0.129 sq ft.
- Tiles: ceil(15.75 ÷ 0.129 × 1.10) ≈ 135 tiles.
At $12 per sq ft of tile (applied to the waste-adjusted area), $15 per adhesive unit, and $8 per grout unit, that example totals roughly $239.
Pattern waste by layout
| Pattern | Waste |
|---|---|
| Straight lay | 10% |
| Diagonal | 15% |
| Herringbone | 20% |
Measuring your backsplash
- Counter runs — one entry per straight run of counter, in feet.
- Height — one value applied to every run; measure your actual counter-to-cabinet gap if going full height.
- Openings — subtract windows or large cutouts, not standard outlets.
- Edge trim — not included here; see the FAQ below on bullnose and edge trim.
How much does a backsplash cost?
Rather than quoting a national average that's stale the day it's published, this calculator prices the job from what you actually enter. Give a tile price per square foot, plus adhesive and grout coverage and price per unit — each is itemized and totaled. The estimate doesn't include edge trim, outlet extenders, or installation labor.
Frequently asked questions
What's a standard backsplash height — 4 in strip vs full 18 in counter-to-cabinet coverage?
A 4 inch strip is the minimal traditional option, covering just the counter edge. Full-height backsplash, filling the whole gap to the upper cabinets — commonly around 18 inches, though it varies — is the more popular modern choice. Measure your own gap rather than assuming 18 inches.
How much extra for an accent or mosaic pattern?
Mosaic sheets often need less waste, since a flexible sheet bends around outlets and corners. A decorative accent band usually needs more, often 15–20%, similar to a diagonal or herringbone layout — run it through this calculator separately if it differs from your field tile.
Do outlet cutouts need to be subtracted?
Generally no, for standard outlets. Tiles get notched around the box rather than removed, so the lost area is small and usually absorbed within the standard waste allowance. Only subtract larger openings like windows or niches.
Should I add bullnose or edge trim?
Yes, on any exposed edge not covered by a cabinet, appliance or wall corner — most often the top edge of a partial-height backsplash. It's priced separately by linear foot and isn't included in this calculator's figures.