How to use this shower tile square footage calculator
A shower alcove, walk-in shower, or a tiled shower with more than one wall or a separate floor.
- Add the finished room, wall, floor, or ceiling dimensions. Split irregular areas into non-overlapping rectangles.
- Choose the measurement unit, enter the tile details, and select a waste percentage that suits the layout.
- Use the coverage printed on the manufacturer's box, then calculate to see area, tile count, and the whole boxes to order.
Measure before you estimate
Measure the finished tile height on each wall and its width along the wall; do not assume the three walls are identical. Add the shower floor as its own rectangle. Enter a window or other untiled opening as a deduction. If wall and floor tile differ, calculate them separately so each uses the correct tile dimensions and package coverage.
How the calculation works
For each wall or floor section, multiply width by height (or floor length by width). Sum the surfaces, subtract opening areas, apply waste, and divide by the face coverage per tile or manufacturer coverage per box. The estimate rounds whole tiles and boxes upward.
Worked example
Example: three walls and a shower floor
Two walls are 3 ft × 7 ft, the back wall is 5 ft × 7 ft, and the floor is 5 ft × 3 ft.
Working: Walls total 77 sq ft and the floor is 15 sq ft, for 92 sq ft before deductions. A 2 ft × 2 ft window removes 4 sq ft, leaving 88 sq ft. With 10% waste, plan on 96.8 sq ft, then round boxes using the coverage on each tile package.
Common measurement mistakes
- Using the rough framing height instead of the finished tiled height.
- Forgetting the shower floor or counting a wall twice at the inside corner.
- Applying one tile's coverage to both walls and floor when they use different products.
Choosing a tile waste percentage
A straight stacked layout with few obstacles can use a smaller allowance than a niche-heavy shower or a diagonal pattern. Many projects start around 10%; 15% or more may be appropriate for small-format tile, multiple niches, sloping cuts, or matching future repairs. Confirm the allowance with the installer.
Always check the product's actual coverage and installation instructions before buying. Cuts, breakage, grout joints, package quantities, and future repair stock can change the final quantity.
Quick answers
Frequently asked questions
Do I include the shower floor?
Yes, if you are estimating tile for it. Add the floor as a separate surface so its area is included; if it uses another tile product, estimate that product separately.
Can I subtract a shower window?
Yes. Enter its finished width and height as an opening deduction. For niches or benches, estimate each tiled face that changes the net area; complex details may need installer judgment.
Should wall and floor tile use the same waste allowance?
Not necessarily. The floor slope, drain cuts, tile size, and layout can change waste. When products differ, run separate estimates with allowances suited to each surface.
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