The size of grout lines for tile is something that comes up on almost every tile installation. The secret no professional will tell you is there is really no set or absolute proper size for your grout lines. There are some guidelines that need to be followed but the actual size is more of a personal choice than it is a set width.

Grout line guidelines

Since grout line widths are generally a personal preference I’ll let you know what mine are. I separate most tiles into three different categories:

  • Small format tile – Tiles up to and including 8 X 8 inches square.
  • Regular – 12 X 12 up to 16 X 16 inches square.
  • Large format tile – 18 X 18 inches and larger.

These are not technically official category names for tile sizes – it’s just what I call them. I’m weird like that.

Small format tile

A lot of smaller format tiles are self-spacing. That means that on either two or four sides of each tile there are what are called “lugs”. Lugged tile have small bumps or protrusions on the sides which are set directly against the tile next to it. Most of these tiles are made specifically for vertical applications, those are shower walls, backsplashes, etc., rather than floors.

The lugs on the tiles allow them to be stacked atop one another and keep the grout lines consistent throughout the installation. For tiles with lugs on only two sides of each tile you must make sure they are all stacked in the same direction, that the lugs are not butted against each other. Normally the lugs will create grout lines that are 1/32 to 1/16 of an inch.

For small format tiles that do not have lugs I will usually use 1/16″ spacers. Depending upon the texture and consistency of the tiles I may use 1/8″ spacers on occasion. For instance 8 inch slate tiles will usually look better with a slightly larger grout line.

If you prefer larger grout lines but have lugged tiles – don’t panic. You can still use spacers with the lugs. To ensure consistency you need to make sure that you either put the spacers between all the lugs or between the spaces the lugs are not. In other words do not put a spacer between the lugs on one tile and between spaces where there are not lugs on another. To figure out the size of your grout lines you also need to add the size of the lugs to the size of the spacer if you use the spacers between them.

Regular format

Regular format tiles are what I install on most of my jobs. More often than not I will use 1/16″ grout lines on vertical surfaces and 1/8″ lines on floors. I just think it looks better and as long as the tile is consistent enough, that’s what I’ll use. I will usually use the smallest grout line the tile will allow.

The best way to figure out how small you can go is to lay out nine tiles in a square and measure from corner to corner in both directions. If they are within 1/16 inch you can go that small with your grout lines. Some tiles such as slate and some quarry tiles will not be consistent enough to use a grout line that small. The largest grout line I will use is 3/16″ unless otherwise specified by the builder or customer.

Large format

Large format tiles are a bit tricky. These, more than either of the other two, are more dependent upon the tile itself. While most people will purchase larger format tiles specifically because they do not want a lot of grout lines, sometimes the tile will not allow it. Although this is rarely a problem, you need to be aware of it and make sure you check the tiles before you try to go with a very small grout line.

The easiest way to check larger format tiles is simply to measure corner to corner in each direction to ensure squareness. As long as they are the same in both directions, they’re square. Then measure several different tiles from different boxes. With a very good tile you should get exactly the same measurement every time. If that’s the case, you can use a 1/16″ grout line and not have any problems.

Large format tiles with 1/16″ or 1/32″ grout lines and a grout that matches the tile color closely looks great! If done correctly it will almost look like a single large slab of tile.

Which do you prefer?

As you can see there is really no absolute answer. If you like smaller grout lines, as long as the tile will allow it, use them. If you prefer larger, use larger. As a general rule do not go larger than 3/16″ although under certain circumstances such as some slates and quarry tiles, 1/4″ is acceptable.

If you choose to use smaller grout lines you must ensure the tile will allow it. If you don’t you may end up with lines that “jog”. That means the lines will not be perfectly straight and will jump over just a bit with every tile due to inconsistencies in tile sizes.

If you prefer larger grout lines you need to take into consideration the “grid effect”. If you do not use a grout that somewhat matches the tile color you may end up with an installation that looks more like a grid made of grout than tile with a grout accent. The smaller the tile, the more pronounced this effect may become.

No matter which you choose, you must make sure you use the correct type of grout. If your grout is chosen and installed correctly your good tile installation can turn into a great one. Make sure you consider your grout as much as you consider your tile. It can make or break your whole look.

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  • Hayley Webb

    Hello. We just had a 24×24 in. tile installed with a 1/8 in. grout line. Unfortunately, it is a straight-edged tile (not beveled), and now the tile is not level, despite the tile company using extra levelers. (We can see the black lines of the tiles raised up.) We found out today that the minimum grout line the manufacturer recommends is 3/16”. Is the only solution to increase the grout lines or do I just need to find a better installer?

    • Roger

      Hi Hayley,

      It honestly depends mostly on the consistency of the tile and the flatness of the substrate. I’ve had tiles that recommended 3/16″ grout lines and installed it flat with less than 1/8″, because they were consistent in both size and thickness.
      That said, a LOT also depends on your installer. The levelers are simply a tool, they do not make a subpar installation better just because they’re used.
      If your tiles are consistently sized, and I mean VERY consistent, then the issue is likely with your installer.

  • Hiten Patel

    Hi Roger,
    Thanks for your previous reply for my 30×60 marble look tile grout line. Now install is done and discussion with tile installer for grout level. Installer is saying it will small sag between tile edge. I did some search and want to have grout level flush to tile edge (straight from edge to edge) because of rectified edge.
    Do you see any issue to have flush grout 1/16 size for rectified tile?
    Installer seems to have issue how to make it flush grout with cleaning process with soft sponge?
    Appreciated your input.
    Thanks
    Hiten

    • Roger

      Hi Hiten,

      What you’re talking about isn’t a thing. :D

      There will ALWAYS be sag between the tile edges, it’s completely normal. It is due to the fact that grout shrinks as it cures. This is tile, this is the way it’s done. Trying to have it flush creates a top layer of grout which will be easily damaged as well.
      Accept the sag. (I NEVER thought I would type those words…)

  • Doug

    I have a bathroom that has 12×12 ceramic tile. The grout lines were not cleaned out enough. Is there anything I can do to correct this or does it have to be redone?

    • Roger

      Hi Doug,

      Do you mean the grout is too high in the grout lines? Like – too much grout? If that’s the case – you can sand it down. Sandpaper will remove grout. Get some 120 grit, wrap it around a beer can (or coke, whatever) and sand down the lines. It’ll give you nice, even, consistent grout lines.

  • Adolfo

    I have a porcelain 13“ x 13“ called majestic mount AYO4. (Dale Tile)I am installing it at 33% brick pattern Can I use a 1/8 grout joint even though it says 3/16 when installing tile with a length 15 inch or greater in a staggered brick joint pattern.? It is for a shower wall and I would like to keep the joints as small as possible. Thank you in advance

    • Roger

      Hi Adolfo,

      Yes, provided the tile does not vary so much that your grout lines will noticeably vary once installed. 1/8″ is normally the size I use with nearly everything. It is rarely an issue.

  • Hiten

    Hi Roger,
    I am installing 30” x 60” rectified porcelain tile. It is made in Spain by TAU manufacturer and good quality perfect square marble look tile.
    Deciding grout line either 1/16 or 1/32. Some installer said that they can do 1/32. Tile supplier and manufacturer suggest 1/16 as minimum and reason is to have good bond between tile.
    What do you think as risk or issue going with 1/32 grouse? Is 1/16 grouse is easy to clean compare to 1/32 grout?

    • Roger

      Hi Hiten,

      Grout cleaning is grout cleaning, regardless of the size. It’s just more grout to clean or less grout. :) 1/32″ CAN be done, but it’s an EXACTING installation. But non-sanded grout, done correctly, is not an issue at all with grout lines that small. Tile supplier is talking out of his ass. :D

  • Pam

    Thank you for your article. Makes perfect sense!

  • David

    Hi Allison. I would say READ THE ALREADY AMSWERED COMMENTS because I did and by the answers that have been answered in the past comments. It sounds to me that Yes the tile guys were doing the right thing. This man Rodger has already stated several times that some tiles manufactured have the little nubs and they can be played this way
    I mean not to be a smart *** I am certainly just trying to help because I read many of his answers to previous comments. Also i am not sure why you wouldn’t trust the man that WAS laying your tile
    What would he have to gain by messing us your home, your job

    • LaNell Barrett

      What many contractors have to gain by sloppy work?
      Because of a few reasons. They’ll have your money and not be around if/when it fails. They don’t know and don’t care to know. They do bad work in their own houses for that matter.
      That’s why I at least try and know enough to question workers. Or, better yet…read snd watch EVERYTHING I can. Then do it myself.

      • Roger

        LaNell is correct – they are in it strictly for the paycheck. They don’t have the knowledge, desire or education to do it properly. After 2008 when the housing market began to rise again any jackass could go to home depot, buy a bucket and a trowel and call themselves a contractor.
        There are a LOT of them – they keep me in business. They keep a LOT of truly professional tile contractors in business. In 25 years I have torn out exactly seven showers that were built properly with zero problems – they just wanted different tile. EVERY OTHER ONE, in 25 years (and that is literally thousands) have had some sort of improper installation issues. That is 99% of my business, replacing a shower because it has some sort of issue.
        It isn’t necessarily having something to gain for messing up. A LOT of these guys actually think they are doing it correctly (that is one main reason I started this site), what they do gain, however, is a paycheck.

  • Patrick

    Thank you

  • Patrick Kelly

    Roger,
    I am renovating my laundry room. I have used 12X24 tiles for the floor. There is a nook where the utility sink is located. The approximate size is 27 1/8” (left), 22 ¾” (back) and 23 ¾” (right). I want to use the same tiles with a 1/8″ grout line. I want to be able to start the tile on the left side and wrap it around to the right hand side. From what I can calculate using the 1/3 offset rule, I will have some small pieces throughout the nook. Is there a better way to do this?
    Thanks.

    • Roger

      Hi Patrick,

      The best way to eliminate smaller pieces with 1/3 offset is to try and shift the layout by either 1/3 or 1/2 of a tile. Sometimes it works, sometimes it doesn’t. If you can’t eliminate them it normally looks best with the installation centered.

  • Larry

    I have been trying to find out about the space between 4×4 ceramic tile for a table. There seems to be a lot of information on all other sizes except the 4×4. I am truly a novice when it comes to laying tile. Thanks.

    • Roger

      Hi Larry,

      It depends on the particular 4×4. If it’s handmade it normally requires AT LEAST 3/16″. If it’s manufactured (consistently sized) then normally 1/8″ or 1/16″. If it has ‘nubs’ on it, then the tile’s nubs are butted to one another. With any of the above you can use spacers of any size to get the look you want provided it is larger than I’ve stated, those are minimum sizes.

      • Larry

        Roger, thanks so much. It is Mexican handmade and you answered my question. I do appreciate it. So nice having one I can ask.

      • Larry

        Thanks so much Roger.

  • Van

    Hello,
    I inherited 18×18 porcelain tile from a family member which I will be installing on the floor of my kitchen and 2 baths. What size spacing and what type of grout would you use for this tile?
    Many thanks

    • Roger

      Hi Van,

      If you read the article above it will tell you about the spacing. I would likely use 1/8″ provided the tile allows for it. Here is info about the grout: What type of grout to use?

  • James

    I have 13×13 tiles I am laying on a bathroom floor. It is a cheaper tile and the edges are slightly beveled. This means when I put an 1/8″ spacer in, the gap at surface level ends up being just over 3/16″. I prefer the look of 1/8″ grout lines so is there any problem with using 1/16″ spacers to get just over 1/8″ gap at the surface? The tiles sizes are pretty uniform (less than 1/16″ difference measuring 3 diagonally by your method) Would you recommend sanded or unsanded grout?
    Surprisingly I can find no info online about this. I can’t be the first person to notice that beveled edges make the spacing/grout rules ambiguous. Thank You!

    • Roger

      Hi James,

      With beveled edges the grout is intended to be flush with the bottom corner of the bevel, not with the surface of the tile. So your grout lines will still be whatever size spacer you use. If you try to grout flush with the surface of the tile the grout over the edge of that bevel will eventually crack out, since it doesn’t really have anything to bond to long-term. Then you end up with grout lines with cracks all the way along the edge. Yes, you can use 1/16″ spacers if you want, but the grout will still need to be only flush with the bottom edge of the bevel.

      • James

        Thanks for the reply but I may not have been entirely clear. This is just completely standard run of the mill square floor tile. “Beveled” may have been the wrong word since I am not talking about an intentional design feature, just the fact that the raw edges flare out slightly as a side effect of manufacturing. If you looked at the tile in profile is very slightly trapezoidal, not rectangular. Therefore if I push a 1/16″ spacer all the way to the floor, the gap at surface level is closer to 1/8″.

        • Roger

          Ah, gotcha. You will need to have space between them, but you can use as small a spacer as you want. You just want to ensure that the tiles are not butted to one another.

  • victoria

    I attemoted my first tile job in guest bathrroom floor. It is small just 5X5. We used 12X24 high gloss porcelein tiles with 1/16 grout lines. I just finished the grout work but now i am nervous I did not “smoosh” enough polyblend into the grout line. I used grout float at 45 degree angle to fill but now I am wondering if I had enough “passes” over the lines. What are your thoughts on this? Obviously, I can not see the lines to see if they are 2/3 of tile full. I am guessing the worst that would happen is grout would eventually crack and I would have to scrape out old and replace with new. I am really not interested in that due to rectified edges but I guess time will tell Thanks.

    • Roger

      Hi Victoria,

      If you have any areas that have a ‘bridge’ of grout, it will normally show within the first week. If you have any lines that are not full enough, it will show the next day after the grout cures. It will be a shallow spot in the grout itself, and it will be noticeable. If you don’t see that you’re fine.

  • Johnny

    I’m using a 4×8 glaze wall tile with lugs/tabs what’s the joint size recommendation for that particular tile please advise

    • Roger

      Hi Johnny,

      The correct way to install those is to stack them on one another. The lugs create the grout line – normally a bit over 1/32.

      • Johnny

        Yea a 1/16 of an inch at the showers

  • Pam

    I am installing a Marazzi 6×36 mixed with 9×36 wood look tile ( cathedral heights nobility ) in entry kitchen family , laundry and bath. I was told by installer he recommends 1/8 over 1/16 said don’t get the possible wavy joints .. I like the more wood look but want to do what’s best. Also said use a maupi colorfast grout. Keeps color better without constant sealing. Thoughts

    • Roger

      Hi Pam,

      Your installer is correct on both counts. With tile that size you need a larger grout line due to inconsistencies in the cooling process of the tile. Larger grout lines will compensate for that. Mapei does not have a grout called ‘colorfast’ (not sure what particular grout you’re referring to), but they do have a few different color-consistent grouts that work very well.