Shower Tile Calculator - Walls, Pan, Curb, Niche & Cost

How to use it

1. Pick the shape you are tiling: alcove walk-in, tub surround, corner walk-in, or custom walls.
2. Enter the width, the depth and the tile height. Leave the to-ceiling toggle on and the height follows the ceiling.
3. Set the field tile size and how many tiles are in a box, then the mosaic sheet size for the pan.
4. Add the niche, the curb girth and a bench if you have them. The niche adds area; it is never a deduction.
5. Tick the edges that get a profile. The tool turns the linear feet into whole sticks with a cut plan.
6. Choose the waterproofing: liquid membrane, sheet membrane, or a foam pan tray. The coverage figures are editable, so match them to the pail you are actually buying.
7. Read the buy list in the rail, then open the takeoff table below to see every surface and how it adds to the total.
8. Type your own prices into the ledger for a planning total. Nothing is a quote.

At a glance

• Alcove walk-in, 60 in wide, 36 in deep, tiled to a 96 in ceiling, 12x24 field tile at 8 a box, 12x12 mosaic pan, one 12x24x3.5 in niche, 60 in curb at a 14 in girth: 88.00 sq ft of wall becomes 112.58 sq ft of tiled surface across 6 surfaces. 8 boxes of field tile (57 tiles, 7 spare), 17 mosaic sheets, 4 trim sticks off 27.00 ft of exposed edge, 3 one gallon pails of liquid membrane, 7 backer sheets, 2 bags of thinset and 9.74 lb of grout. About $871.84 at the seeded prices, of which the tile is $256.00.
• Tub surround, 60 in wide, 30 in deep, tiled 60 in above the deck, same 12x24 tile, no pan, no curb, no niche: 50.00 sq ft over 3 surfaces. 4 boxes (29 tiles, 3 spare), 20.00 ft of edge profile cut from 3 sticks, 1 gallon of membrane, 4 backer sheets, 1 bag of thinset and 2.74 lb of grout. About $393.81.
• The same alcove with a 60 x 16 in bench, 17 in face: 119.67 sq ft over 8 surfaces. The bench adds a 6.67 sq ft top and a 7.08 sq ft face and takes its own 6.67 sq ft footprint back off the pan, so the pan drops to 10 mosaic sheets while the field tile goes to 9 boxes and the thinset to 3 bags. About $905.41.
• Corner walk-in, 60 by 36 in, two walls, curb on two sides: 64.00 sq ft of wall becomes 92.08 sq ft over 5 surfaces, because the curb now runs 96 in and takes 9.33 sq ft on its own. 6 boxes, 17 mosaic sheets, 4 sticks, 2 pails, 5 backer sheets.

How the math works

Every surface is measured in inches and converted to square feet by dividing by 144, then carried as a signed row so the takeoff adds up in front of you. A wall panel is width x height. A niche adds its back, W x H, plus its returns, 2 x (W + H) x depth, and the opening is not subtracted because the tile cut out of it cannot be reused. A curb is length x (top + inside + outside), three faces rather than one. The pan is width x depth. A bench adds a top and a face and takes its footprint back off the pan, which is why a bench costs less than it looks. Each row carries its own waste rate, and the purchase is assembled by material: field tile square feet are summed with waste and divided by the tile's own area to get tiles, then by the box coverage to get boxes; the pan's square feet go to mosaic sheets the same way. Trim is the sum of the edges you tick, cut into real pieces and packed onto sticks by decreasing next-fit, the way a person cuts at a saw. Liquid membrane divides the wall plane by the wall rate and the pan by its heavier pan rate. Backer is the wall gross plus the curb, since the niche box is lined from offcuts and the pan is a mortar bed or a foam tray. Grout comes off the joint geometry: a square foot of tile carries 144 x (L + W) / (L x W) inches of joint, each inch of it joint width x tile depth of cross section, at about 0.065 lb per cubic inch. Every displayed breakdown is apportioned by largest remainder, so the rows you can see always add to the total above them.

1. 1. Measure each panel, in inches, and keep them apart

   A 60 in wide by 36 in deep alcove tiled to a 96 in ceiling is three panels, not one number: the back is 60 x 96 = 40.00 sq ft and each side is 36 x 96 = 24.00 sq ft, for 88.00 sq ft of wall. Enter feet and inches in their own boxes. A shower measured as 5.6 ft because it is 5 ft 6 in is out by half an inch a wall, and on this geometry that is most of a tile.

2. 2. Add the niche back and its returns. Never subtract the hole

   A 12 x 24 in niche with a 3.5 in return adds 12 x 24 / 144 = 2.00 sq ft of back plus 2 x (12 + 24) x 3.5 / 144 = 1.75 sq ft of returns, so 3.75 sq ft goes on, and the wall plane becomes 91.75 sq ft. Nothing comes off for the opening. The tile you cut out of a 12 by 24 in hole is four odd offcuts, and a shower wall gives you nowhere to use them. Treat the niche as a small extra room with five surfaces, because that is what it is.

3. 3. Take the curb on three faces

   A curb is not a strip on the floor. It has a top, an inside face looking into the shower and an outside face down to the bathroom floor, and all three get tile. At the default 4 in top, 4 in inside and 6 in outside that is a 14 in girth, so a 60 in curb is 60 x 14 / 144 = 5.83 sq ft. On a corner shower the curb runs both open sides, 96 in here, and takes 9.33 sq ft on its own. That single surface is bigger than most people's whole allowance for extras.

4. 4. Buy the pan in sheets, not square feet

   The pan slopes to the drain, so it wants a small format that can follow the slope. A 60 x 36 in pan is 15.00 sq ft, and at 10 percent waste that is 16.50 sq ft, which buys 17 sheets of 12 x 12 in mosaic. Mosaic sheets are nominal: a 12 in sheet is usually a touch under 12 in so the sheet-to-sheet joint matches the chip joints, and the coverage printed on the box is what you should type in here.

5. 5. Waste by surface, not one number for the job

   Walls at 15 percent, the pan at 10 percent and the curb and bench at 20 percent. Showers run above the generic 10 percent because the walls are short and cut-heavy: a 60 in wall in 12 in tile is five clean columns, but a 36 in return with a niche in it is nearly all cuts. Straight-laid large format on a big wall can drop to 12 percent. Herringbone and diagonal should go to 20. The default 15 / 10 / 20 turns 91.75 sq ft of wall plane and 5.83 sq ft of curb into 105.51 + 7.00 = 112.51 sq ft to buy.

6. 6. Tiles, then boxes, then leftovers

   A 12 x 24 in tile is 2.00 sq ft, so 112.51 sq ft is 57 tiles, and at 8 tiles a box that is 8 boxes, 64 tiles, 7 spare. Order in boxes, always: shade lots differ between runs, and a box bought in March will not match a box bought in June. Check the coverage printed on the box rather than trusting the nominal size, because a 12 x 24 box is anywhere from 15 to 16 sq ft depending on the maker.

7. 7. Turn exposed edges into sticks with a cut plan

   The default alcove has 27.00 ft of exposed edge: two open verticals at 96 in, the 60 in curb front, and the 72 in perimeter of the niche. Total length divided by the 98.5 in stick length says 3.3 sticks, so 4. The cut plan says 4 too, but for a different reason and with a different pile of offcut: two sticks each give up one 96 in vertical and 2.5 in of scrap, the third gives 60 + 24 + 12, and the fourth gives 24 + 12 and keeps a 62.5 in tail. Verticals are never spliced, because a joint in a full-height run is the first thing anyone sees.

8. 8. Waterproof at the label's coverage, not the headline one

   Liquid membrane sells on a coverage figure of about 110 sq ft a gallon, and that is per coat. The system is two coats, so the wall figure to plan with is 55 sq ft a gallon, and pans get more material still, about 40. On the default that is 97.58 / 55 = 1.77 gal for the walls, curb and niche plus 15.00 / 40 = 0.38 gal for the pan, which is 2.15 gal, so three one gallon pails or one 3.5 gal pail. Both figures are editable here, and the pail in your hand outranks both of them.

9. 9. Backer, screws and tape

   Cement backer goes on the wall gross plus the curb, 93.83 sq ft here, which at 15 sq ft a 3 x 5 sheet is 7 sheets. The niche box gets lined from offcuts. Screws run about 35 a sheet, so 245, which is one 250 pack. Tape covers every change of plane, 2 inside corners at 96 in plus the 132 in bottom run, so 27 ft, and one seam per extra sheet, 18 ft more, for 45 ft on a 50 ft roll.

10. 10. Thinset and grout, priced by the notch and the joint

    A 50 lb bag covers about 55 sq ft at the 1/4 x 3/8 in notch large format wants, and about 80 sq ft at the 1/4 x 1/4 in notch mosaic wants, so 97.58 / 55 + 15.00 / 80 = 1.96 bags, which is 2. Grout is the surprise. 97.58 sq ft of 12 x 24 wall tile takes 5.35 lb, while 15.00 sq ft of 2 in mosaic takes 4.39 lb, because joint length per square foot goes as (L + W) / (L x W) and a 2 in chip carries eight times the joint of a 12 x 24 tile. The pan is a seventh of the area and nearly half the grout.

Worked scenarios, start to finish

Real jobs with the numbers carried all the way through, so you can see how the estimate is built and check your own figures against them.

The judgement calls a pro makes

Decisions the tool cannot make for you, and how someone who does this for a living thinks them through.

Whether to subtract the niche opening

This tool does not, and the reason is offcuts rather than geometry. Cutting a 12 by 24 in hole out of a wall in 12 x 24 tile leaves you four L-shaped or narrow pieces from the courses that cross the opening, and a shower wall has no discreet place to use them. If you are running a small mosaic or a 3 x 6 subway where the cuts around an opening genuinely go back into the field, you can drop the wall waste from 15 to about 12 percent to reflect it. Subtracting the opening outright is how people end up a box short.

Profile, bullnose or a mitered edge

A metal profile such as a Schluter Jolly is the forgiving choice: it hides an imperfect cut, it comes in a 98.5 in stick, and the tool can plan it. Bullnose is only available if your tile line makes it, which large format porcelain usually does not. A mitered edge, where two tiles are cut at 45 degrees and folded around the corner, is the best looking and the least forgiving, needs a wet saw and a steady hand, and adds about 5 percent to the waste on every edge you do it to. Pick before you order, because the profile has to be set with the tile, not after.

Mosaic or large format on the pan

A pan slopes about a quarter inch a foot toward the drain, in more than one plane. Mosaic conforms because each chip can sit at its own angle; a 12 x 24 tile cannot, and forcing it leaves lippage and a puddle. If you want large format on the floor of a shower, the way to do it is a linear drain with a single-plane slope, which is a design decision made before the framing. Whatever you choose, check the DCOF rating: a wet floor wants 0.42 or better, and plenty of pretty wall tile is nowhere near it.

Liquid membrane, sheet membrane or a foam pan

Liquid is the cheapest and the most forgiving of an odd shape, but it is only waterproof at the right film thickness, which means two coats and a colour change you have to actually look for. Sheet membrane goes on at a known thickness the moment it is bonded, which takes the guesswork out, and it costs more: 2 rolls at the seeded price is $378.00 against $179.94 of liquid. A foam pan tray takes the pan out of the equation entirely and is the fastest route to a flat, correctly sloped floor, at $349.00 for the tray. The tool prices all three so the decision is a number rather than an opinion.

To the ceiling or stop at 8 ft

Tiling to the ceiling removes the top edge entirely, which is 132 in of profile on this alcove and a horizontal line that will show every millimetre of a level error. Stopping below the ceiling puts that edge back and gives you a paintable band above it, which is cheaper and easier to repair. On the default the difference is real but small: the 96 in tile height is already the ceiling, so there is no top edge; drop it to 84 in and you add 11 ft of trim and take about 11 sq ft off the tile. Steam showers are a separate matter and always go to the ceiling.

Sanded or unsanded grout

The joint width decides it, not the tile. Under 1/8 in use unsanded, because sand will not fit and the joint will be pinholed. At 1/8 in and above use sanded, because unsanded grout shrinks and cracks in a wide joint. The default here is a 1/8 in joint, which is the boundary, and either will work if it is mixed properly. The grout weight in the result assumes a sanded density of about 0.065 lb per cubic inch, and if you switch to an epoxy or a premixed urethane you should type that product's own coverage in instead.

How much offset on large format walls

A 50 percent running bond on a 24 in tile puts the middle of one tile against the end of the next, and porcelain that size almost always has a slight crown, so the two ends sit proud of the middle and you get lippage down the whole wall. Most large format manufacturers now specify a maximum offset of 33 percent for exactly this reason, and a third offset also looks more deliberate. It does not change the tile count, but it does change the cut pattern, so it belongs in the waste conversation.

Common mistakes, and the fix

• × Buying from wall area alone, because that is the number every tile shop widget prints.

  ✓ Add the niche, the curb and the pan. On the default alcove that is the difference between 88.00 and 112.58 sq ft, 28 percent more tiled surface. Buying 88.00 plus 15 percent gets you 7 boxes when the job needs 8, and no mosaic at all.

• × Treating the curb as a strip of floor.

  ✓ A curb has a top, an inside face and an outside face. At a 14 in girth a 60 in curb is 5.83 sq ft; on a corner shower it runs 96 in and takes 9.33 sq ft, which is more than a whole box of 12 x 24.

• × Subtracting the niche opening from the wall.

  ✓ The niche adds 3.75 sq ft on the default: its back plus its four returns. The tile cut out of the hole is scrap on a shower wall, so nothing comes off.

• × Using a floor's 10 percent waste factor on short, cut-heavy shower walls.

  ✓ Walls default to 15 percent here, the curb and bench to 20, and the pan to 10. A 36 in return wall with a niche in it is nearly all cuts, and a 10 percent allowance does not cover it.

• × One coat of liquid membrane, because the pail says 110 sq ft.

  ✓ That figure is per coat and the system is two coats. Plan at 55 sq ft a gallon for walls and about 40 for the pan, and look for the colour change that tells you the film is thick enough.

• × Pricing the pan mosaic at field tile prices.

  ✓ Mosaic is sold by the sheet and costs far more per square foot. 15.00 sq ft of pan is 17 sheets and $135.66 at the seeded price, which is over half what 91.75 sq ft of wall tile costs.

• × Splicing a trim profile part way up a vertical edge.

  ✓ A 96 in vertical comes off a single 98.5 in stick with 2.5 in to spare. The cut plan here never splices a vertical, and if the run is longer than a stick it says so instead of quietly joining it.

• × Forgetting that a bench takes area off the pan it stands on.

  ✓ A 60 x 16 in bench adds 13.75 sq ft of top and face and removes 6.67 sq ft of pan, which is seven mosaic sheets. The net addition is the face alone.

Material and unit specifics

12 x 24 in wall tile and box coverage

12 x 24 is the default wall format for a shower because it covers ground fast and has few joints. Nominal area is 2.00 sq ft, but box coverage varies between makers, roughly 15 to 16 sq ft for an 8 piece box, and some lines box 6 or 10. Type in what the box says rather than trusting the count, and buy full boxes so the shade lot matches.

Mosaic sheets, nominal against actual

A 12 in mosaic sheet is normally cut a joint width under 12 in, so that when sheets butt together the sheet-to-sheet joint reads the same as the chip joints. The tool takes the sheet size you type as its coverage, so use the box figure, not the name of the product. A 12 x 12 sheet at 1.00 sq ft is the seeded default and the pan on the standard alcove takes 17 of them.

Schluter profile stick length, 98.5 in

The standard trim length is 2.5 m, which is 98.5 in. That is what makes a 96 in vertical work off one stick and why an odd 100 in run suddenly needs two. The stick length is editable because other manufacturers ship 8 ft and 10 ft, and a 10 ft stick changes the cut plan completely.

RedGard coverage, from the manufacturer's own documents

Custom Building Products publishes about 110 sq ft per gallon per coat for walls and requires two coats, so the finished wall system is about 55 sq ft a gallon. Floors and pans are applied heavier and land near 40. Those are the two seeded rates here, both editable, and both worth checking against the pail you buy, because coverage is stated differently by different brands and changes with the substrate.

Cement backer board, 1/2 in on walls

Tile backer for shower walls is 1/2 in board in 3 x 5 ft sheets, 15 sq ft each, fastened with about 35 backer screws a sheet. It is not moisture-resistant drywall, and green board is not a tile backer in a wet area. The tool sizes the wall gross plus the curb and leaves the niche box to offcuts, which is how it gets built in practice.

Seam tape and change of plane

Alkali-resistant mesh tape is sold in 50 ft rolls. Every sheet-to-sheet seam and every change of plane gets taped and filled with thinset before the membrane goes on. On the default that is 27 ft of corner and bottom joint plus 18 ft of field seam, so 45 ft, which is one roll with 5 ft spare.

Thinset coverage by notch

Coverage is a function of the trowel, not the bag. A 50 lb bag of modified thinset covers roughly 55 sq ft at a 1/4 x 3/8 in square notch, which is what a 12 x 24 tile needs, and roughly 80 sq ft at the 1/4 x 1/4 in notch mosaic wants. Large format also wants back buttering, which eats into that figure, so round up rather than down.

Grout density and joint geometry

Sanded grout weighs about 0.065 lb per cubic inch of joint. The volume comes from the tile module: a square foot of tile carries 144 x (L + W) / (L x W) inches of joint. For 12 x 24 that is 18 in a sq ft; for a 2 in mosaic chip it is 144 in, eight times as much. That single ratio is why the 15 sq ft pan takes 4.39 lb of grout while 97.58 sq ft of wall takes 5.35 lb.

Curb girth, and why 14 in is the default

A framed curb is usually two or three 2x4s laid flat, about 4 in wide on top, standing about 4 in above the finished pan on the inside and about 6 in above the bathroom floor on the outside. Add the three and you get the 14 in girth seeded here. Measure your own after the pan is poured, because the inside face is whatever is left above the mortar bed.

Reading your result

The two numbers at the top are the argument: the walls-only figure that page one prints, and the tiled surface you are actually covering. Use the second one to buy. The buy list under it is in the order you will shop it, and every quantity is already rounded up to a real purchasable unit, so 2.15 gallons of membrane is 3 pails and 1.96 bags of thinset is 2 bags. The spare tiles are not slack in the estimate: 7 spare out of 64 is attic stock, and it is the only chance you will ever have of matching a cracked tile in three years, so keep them in the box with the lot number showing. When the answer lands just over a box boundary, look at the waste rate before you order the extra box, because dropping walls from 15 to 12 percent on a straight-laid large format wall is a legitimate change and can be the difference. The ledger is a plan and not a quote: type your own prices in, and read the total as the size of the basket rather than the price of the job.

Limitations

• This page is the wet area only. Rooms, floors, plain walls and backsplashes belong on the tile calculator, and the dry bathroom floor outside the shower belongs on the flooring calculator.
• Steam showers are a different system. They need a continuous vapour barrier, a sloped ceiling and tile to the ceiling, and none of that is modelled here.
• The pan is measured on its plan area. A mortar bed sloping a quarter inch a foot adds well under one percent of surface, but the mud bed volume itself is not sized here.
• Curbless drainage is a plumbing and framing question first. Turning the curb off removes it from the tile takeoff; it does not tell you whether your floor can be recessed.
• Every price is a seed, not a quote, and none of them is live. Prices move by region, by season and by store.
• Coverage figures for membrane, thinset and grout are typical values and vary by product, substrate and trowel. Verify against the label on what you actually buy.
• This is guidance built from manufacturer instructions and common industry practice, not installation advice. Local code, the product's own instructions and your building inspector govern the work.
• Metric is not offered. This is a US page and every constant in it, from the 98.5 in stick to the 3 x 5 ft backer sheet to the 50 lb thinset bag, is the US convention.

Frequently asked questions

How many square feet of tile do I need for a walk-in shower?

For a standard 60 by 36 in alcove tiled to a 96 in ceiling, the walls are 88.00 sq ft, and that is the number most calculators stop at. The tiled surface is 112.58 sq ft, because a 12 x 24 niche adds 3.75 sq ft, a 60 in curb adds 5.83 sq ft across its three faces, and the pan adds 15.00 sq ft that is bought in mosaic rather than field tile. After waste that is 112.51 sq ft of field tile, which is 57 tiles or 8 boxes, plus 17 mosaic sheets for the pan. If you buy against the 88, adding the usual 15 percent gets you 7 boxes when the job needs 8, and no mosaic for the pan at all.

Does a shower niche add tile or subtract it?

It adds. A 12 x 24 in niche with a 3.5 in return adds 2.00 sq ft of back and 1.75 sq ft of returns, so 3.75 sq ft, and if you profile the edges it adds 72 in of trim as well. The instinct to subtract the opening comes from floor tiling, where a cut around an island genuinely goes back into the field. On a shower wall the four pieces you cut out of a niche opening are scrap, so nothing comes off. A niche is a small extra room with five surfaces, and it should be estimated like one.

What waste factor should I use for shower tile?

15 percent on walls, 10 percent on a mosaic pan, and 20 percent on a curb or a bench. Showers run above the generic 10 percent because the panels are short and cut-heavy: a 36 in return wall with a niche in it is nearly all cut tile, and the curb is three narrow strips. Straight-laid large format on a wide wall can come down to 12 percent. Herringbone, diagonal and any pattern that interlocks should go to 20. Every one of those rates is editable here, and each surface carries its own, which is why the default job buys 105.51 sq ft for the walls and 7.00 sq ft for the curb rather than applying one number to everything.

How much RedGard do I need for a shower?

Custom Building Products publishes about 110 sq ft per gallon per coat on walls, and the system is two coats, so plan at 55 sq ft a gallon. Pans are coated heavier, around 40 sq ft a gallon. On the default 60 by 36 in alcove that is 97.58 sq ft of wall, niche and curb at 1.77 gal plus 15.00 sq ft of pan at 0.38 gal, so 2.15 gal in total: three one gallon pails at $59.98 each, or one 3.5 gal pail at $159.98, which the tool flags because it is $19.96 cheaper for the same job. Check the coverage on your own pail before you buy, because it varies by brand and by substrate.

Why does the pan take almost as much grout as the walls?

Because grout fills joints, and joint length per square foot goes as (L + W) / (L x W). A square foot of 12 x 24 tile carries 18 inches of joint. A square foot of 2 in mosaic carries 144 inches, eight times as much. So on the default shower the 15.00 sq ft pan takes 4.39 lb of grout while 97.58 sq ft of wall tile takes 5.35 lb, from a seventh of the area. It still fits in one 25 lb bag here, but on a bigger pan or a smaller chip it is the line that pushes you into a second bag, and it is the reason a job estimated on square footage alone runs out of grout on the floor.

How much does it cost to tile a shower yourself?

At the prices seeded here the default 60 by 36 in walk-in comes to about $871.84 in materials, and the tile is only $256.00 of it. The rest is $135.66 of mosaic, $179.94 of waterproofing, $122.36 of backer board, $88.00 of trim profile, $39.94 of thinset, $19.98 of grout and $29.96 of screws and tape. Move to a $6.50 a sq ft tile and the total goes to $1,447.84, with every other line unchanged. Labour, if you hire it, is commonly quoted at $10 to $25 a sq ft of tiled surface, which on this job is $1,125.83 to $2,814.58, and the tool will show that range as a separate line. Treat all of it as a planning ledger rather than a quote, and type your own prices in.