Shower Tile & Pan Calculator
Calculates walk-in shower tile and waterproofing requirements across shower walls (up to 8 ft high ceiling), sloped shower pan floor (mosaic sheets), shower curb, built-in recessed niche, and Schluter Kerdi or RedGard waterproofing membrane.
Formula
Wall Area = 2 × (L + W) × Height - Door (18 sq ft); Floor Area = L × W; Total Tile = (Walls + Floor) × (1 + Waste %)
1. Gross Wall Area = 2 × (Length + Width) × Tiling Height 2. Net Wall Area = Gross Wall Area - 18 sq ft (shower glass door opening) 3. Shower Pan Floor Area = Length × Width 4. Total Waterproofing Membrane Area = Net Wall Area + Pan Floor + 6 sq ft (curb & niche) 5. Wall Tile Boxes = Ceil((Net Wall Area × (1 + Waste %)) ÷ Box Sq Ft) 6. Pan Floor Mosaic Sheets (1 sq ft/sheet) = Ceil(Pan Floor × (1 + 15% drain cut waste))
Inputs
- Shower Enclosure Length
- Shower Enclosure Width
- Wall Tile Height
- Recessed Storage Niche?
Worked example
Tiling walls to 8 ft ceiling, floor pan with 2x2 mosaics, and installing Schluter Kerdi membrane.
Outcome: Wall area is 110 sq ft (128 gross - 18 door opening). Floor pan is 15 sq ft. Total waterproofing membrane needed: 131 sq ft. Wall tile: 9 boxes of 12x24 porcelain (128 sq ft). Floor pan: 18 sheets of 2x2 mesh mosaic tile.
Why can large 12x24 tiles NOT be used on standard sloped shower pan floors?
Large format tiles cannot bend to form the 1/4" per foot compound 4-way slope required to channel water down into a center drain. Trying to install large tiles causes severe tile lippage or standing water puddles unless a specialized linear trench drain is used.