What Size Grout Line For 12×24 Tile? Select the Ideal Grout Line Width
Picking a grout width for 12 by 24 inch tile trips up a lot of DIY tilers. Go too tight and small flaws show. Go too wide and the look turns busy.
The good news: the right range is narrow.
Short answer: For rectified 12×24 tile, use a 1/16 inch to 1/8 inch grout line. A 1/8 inch joint is the safe default, because it hides the slight warp and the offset layouts these big tiles often use. Drop to 1/16 inch only with very flat tiles and a straight, stacked layout.
Recommended grout width for 12×24 tile
| Situation | Grout width |
|---|---|
| Rectified edge, offset or brick-lay | 1/8 inch |
| Rectified edge, straight stack, very flat tiles | 1/16 inch |
| Non-rectified (pressed) edge | 1/8 inch to 3/16 inch |
| Industry minimum for rectified (TCNA) | 1/8 inch, plus any edge warp |
Why 12×24 tile is tricky
Large-format tile is never perfectly flat.
A 24 inch tile almost always has a slight bow along its length. Lay two side by side and one edge can sit a hair higher than its neighbor. That step is called lippage.
A slightly wider joint absorbs that difference. A hairline joint shows every bit of it.
1/16 inch vs 1/8 inch
These are the two real choices for rectified 12×24 tile.
1/16 inch gives a near-seamless, modern look. It demands very flat tiles, a flat substrate, and patient work.
1/8 inch is the forgiving, pro-friendly default. It hides minor warp and lippage and still looks clean.
Watch your layout
Offset layouts make warp worse.
Stagger 12×24 tile in a brick pattern and the high center of one tile meets the end of the next. Keep the offset to about one third or less, and lean toward a 1/8 inch joint.
Do not go too tight
The TCNA, the US tile standards body, sets 1/8 inch as the minimum for rectified tile, then says to add the amount of warp on the longest edge.
So 1/16 inch is below the official minimum. It can work, but it is an advanced, no-margin choice.
Grout color
Match the grout to the tile for a seamless, larger-looking floor. Pick a contrasting grout to show off the pattern instead.
On big tile with thin joints, a close color match usually looks best.
The Bottom Line
- Use 1/8 inch for almost every 12×24 install, especially offset layouts or less-than-perfect tiles. It is the safe, standard-compliant default.
- Use 1/16 inch only for a straight, stacked layout with very flat rectified tiles and careful prep, when you want the most seamless look.
Related reading: Best Tile Cleaners for Kitchen Backsplashes and Floors, How to Seal Granite, Marble, and Quartz Countertops, and How to Choose a Floor Color.
