Shower Tile Calculator: Square Feet & Cost

This shower tile calculator works out the total square footage (and square meters) of tile you need for a shower’s walls and floor, based on the measurements you enter for each surface. You input the height and width of each wall section and the floor dimensions, and it returns the total area to cover, plus a recommended tile order amount that includes a waste allowance for cuts and breakage. The calculator also estimates the number of 12×12-inch tiles required, which is a common tile size, and lets you adjust the waste percentage to match your skill level and tile pattern.

Formula

The basic formula is simple: for each rectangular surface, multiply its length by its width to get the area in square feet. For a shower, you typically have three wall sections (back, left, right) and a floor. The total area is the sum of all these sections:

Total Area = (Wall1 Height × Wall1 Width) + (Wall2 Height × Wall2 Width) + (Wall3 Height × Wall3 Width) + (Floor Length × Floor Width)

All measurements are in feet, so the result is in square feet. To convert to square meters, multiply by 0.092903. To account for waste (cuts, broken tiles, future repairs), multiply the total area by (1 + waste percentage/100). The number of 12×12 inch tiles is simply the area in square feet, because each tile covers exactly 1 square foot.

Worked Example

Let’s use the default values from the calculator: a shower with one wall 8 ft high by 6 ft wide, two walls 8 ft by 4 ft, and a floor 3 ft by 3 ft, with a 10% waste allowance.

1. Wall 1 area = 8 × 6 = 48 sq ft
2. Wall 2 area = 8 × 4 = 32 sq ft
3. Wall 3 area = 8 × 4 = 32 sq ft
4. Floor area = 3 × 3 = 9 sq ft
5. Total area = 48 + 32 + 32 + 9 = 121 sq ft
6. With 10% waste: 121 × 1.10 = 133.1 sq ft (order about 134 sq ft)
7. 12×12 tiles needed = ceil(133.1) = 134 tiles

So for this shower, you’d order at least 134 square feet of tile, which is 134 individual 12×12 tiles.

How to Measure Your Shower

Accurate measurements are critical. Use a metal tape measure and measure in feet and inches, then convert to decimal feet (e.g., 6 ft 3 in = 6.25 ft). Measure each wall section separately, from the shower pan or tub edge to the ceiling or the height you plan to tile. For the floor, measure the length and width of the shower pan. If your shower has a niche, a bench, or a window, subtract those areas if you won’t tile them, but it’s often simpler to leave them in as extra waste. For a tub surround, measure the three walls above the tub, and skip the floor.

How to Choose the Right Waste Allowance

The waste percentage is not a fixed number; it depends on several factors. For a straight lay (grid pattern) with large tiles and simple cuts, 10% is usually enough. For diagonal patterns, herringbone, or small mosaics, you’ll need more—15% to 20% is common. If your walls are not perfectly square or have many obstacles (outlets, valves, windows), add 5% more. If you’re a DIYer with limited cutting experience, go with 15% or 20%. It’s better to have a few extra tiles than to run short mid-project, because dye lots can vary and matching later is hard.

Common Mistakes and How to Avoid Them

• Mixing units: Don’t mix inches and feet in the same measurement. Convert everything to feet first. For example, 8 ft 6 in = 8.5 ft.
• Forgetting the floor: Many people only measure walls. The floor adds up, especially in a larger shower.
• Rounding too early: Round only at the end. If you round each wall to the nearest foot, you can over- or under-estimate by several square feet.
• Ignoring tile size: The calculator assumes 12×12 tiles. If you use 6×24 inch planks, the number of tiles will differ, but the total square footage remains the same—you just need to convert based on the actual tile size.
• Not accounting for grout lines: Grout lines take up a tiny fraction of area, but for very large tiles with thin grout, the difference is negligible. For small mosaics, you might lose 5% to 10% of the area to grout, so add that to your waste.

Tile Size and Layout Considerations

The area calculation is independent of tile size, but the number of tiles you need is not. For 12×12 inch tiles, one tile covers 1 sq ft, so the number of tiles equals the area in sq ft. For other sizes, divide the area by the area of one tile (in sq ft). For example, a 6×6 inch tile is 0.25 sq ft, so you’d need 4 tiles per sq ft. A 12×24 inch tile is 2 sq ft, so you’d need half a tile per sq ft. Always round up to the nearest whole tile. Also, consider the layout: a running bond (brick) pattern may require more cuts at the ends, so increase waste accordingly.

Cost Estimation

Once you have the total square footage, you can estimate cost by multiplying the area (including waste) by the price per square foot of the tile you like. For example, if tile costs $3 per sq ft and you need 134 sq ft, the tile cost is $402. Don’t forget additional costs: thinset mortar, grout, backer board, waterproofing membrane, and tools. These can add 20%–50% to the material cost. Also, professional installation labor is often charged per square foot, so having the exact area helps you get quotes.

Frequently Asked Questions

How many 12×12 tiles do I need for a 5×5 shower?

If the shower is 5 ft by 5 ft with 8 ft high walls, the wall area is 4 walls × (8×5) = 160 sq ft, plus the floor 25 sq ft = 185 sq ft. With 10% waste, that’s 203.5 sq ft, so you’d need 204 tiles. But if you have a standard 3-wall alcove, adjust accordingly.

Should I measure in inches or feet?

You can use either, but the calculator expects feet. If you measure in inches, divide each dimension by 12 to get feet. For example, 72 inches = 6 ft. Mixing units is the most common error, so stick to one system.

What is the average waste percentage for tile?

For a simple straight lay, 10% is standard. For diagonal or herringbone patterns, 15%–20% is safer. If you have a complex shower with many cutouts, go up to 20%–25%. It’s always better to overestimate slightly.

Does the calculator include the shower pan or just the walls?

This calculator includes both walls and floor. If you’re tiling a tub surround, you can set the floor dimensions to 0 (or just ignore the floor output). Some showers have a prefabricated pan, so you’d only measure the walls.

How do I convert square feet to square meters for tile?

Multiply the square footage by 0.092903. For example, 121 sq ft × 0.092903 = 11.24 m². The calculator does this for you in the second output.

Can I use this calculator for a steam shower or unusual shapes?

This calculator works for rectangular sections. For a steam shower with a bench, niche, or sloped ceiling, break the area into smaller rectangles and add them manually, or use the calculator for the main walls and add the extras separately. For irregular shapes, it’s best to draw a diagram and divide it into rectangles.

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in wall1_h | Wall 1 Height | ft | 8 | 0
in wall1_w | Wall 1 Width | ft | 6 | 0
in wall2_h | Wall 2 Height | ft | 8 | 0
in wall2_w | Wall 2 Width | ft | 4 | 0
in wall3_h | Wall 3 Height | ft | 8 | 0
in wall3_w | Wall 3 Width | ft | 4 | 0
in floor_l | Floor Length | ft | 3 | 0
in floor_w | Floor Width | ft | 3 | 0
in waste | Waste Percent | % | 10 | 0
out area | Total Area | sq ft | wall1_h*wall1_w + wall2_h*wall2_w + wall3_h*wall3_w + floor_l*floor_w | 2
out area_m | Area in sq meters | m² | area * 0.092903 | 2
out tiles_12 | 12x12 Tiles Needed | tiles | ceil(area * (1 + waste/100)) | 0
out order_sqft | Order This Much | sq ft | area * (1 + waste/100) | 2