Backsplash Calculator
Work out how many backsplash tiles a kitchen or bathroom needs — with power outlets deducted and a 15% allowance for the many small cuts around edges and sockets.
A backsplash is a small job with a surprising number of cuts. Every outlet needs a notch, every end needs a trim, and small tiles mean more of them get cut. This calculator is built for exactly that — outlets deducted, wastage set to 15% by default.
Measure each separate run (for example, the wall behind the hob and the wall behind the sink) and add the tile counts together.
Your results
Enter your measurements and press Calculate.
Quantities are rounded up to whole tiles, planks, boxes or bags, after the wastage allowance. Cost appears only when you enter a price.
Formula
All lengths are converted to a single unit before the calculation: 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 ft² = 0.09290304 m², 1 yd² = 9 ft². Material quantities are rounded up — you cannot buy part of a tile, plank or bag.
How to use this calculator
- Measure the full length of the backsplash run and its height (usually counter to cabinet).
- Count the power outlets and switches on that wall.
- Enter your tile size — 3 × 6 in subway is the most common.
- Keep wastage at 15% unless the run is long and straight, with no outlets.
Worked example
| Backsplash | 10 ft long × 18 in (1.5 ft) high = 15 ft² |
|---|---|
| Outlets | 2 × 0.086 ft² = 0.172 ft² deducted |
| Net area | 15 − 0.172 = 14.83 ft² |
| Tile | 3 in × 6 in = 0.125 ft² per tile |
| Raw tiles | 14.83 ÷ 0.125 = 118.6 tiles |
| Tiles with 15% wastage | ⌈118.6 × 1.15⌉ = 137 tiles |
Check it by hand: every step above uses the formula in the box. If your numbers match the example inputs but the calculator gives a different answer, please report it via the contact page.
Frequently asked questions
Why is backsplash wastage 15%?
Backsplash tiles are small, so a higher share of them gets cut — around outlets, at the ends of each run, and where the counter meets the wall. Long straight runs with few outlets can use 10%.
How high should a kitchen backsplash be?
The standard is 18 in (450 mm) from the countertop to the underside of the wall cabinets. Full-height backsplashes run from counter to ceiling, or to the underside of a range hood.
Do I need to remove outlet covers before tiling?
Yes. Remove the cover plates, tile up to the outlet box, then refit the plates over the tiles. You may need longer outlet screws and box extenders so the outlet sits flush with the finished tile face.
Can I use the same tile on the backsplash and the floor?
You can, but floor tiles are usually larger and heavier. Backsplashes suit smaller, lighter tiles that are easy to cut around outlets. Check the tile is rated for wall use.
Related calculators
Estimates only. Results are for planning. Measure twice, confirm box coverage and tile sizes on the packaging you buy, and follow the manufacturer's instructions. See the disclaimer.