First time installing kitchen cabinets. Uppers went it fine, no trouble at all. With the base cabinets, though, I have one wall that is out of square about 1.5 inches in 12 feet.

Should I just be making them level for the countertop and plumb, as tight to the wall as possible, or should the entire run of cabinets along that wall be perfectly square to the perpendicular row? Said differently, should I be shimming them out from the wall at each cabinet so that when I get to the last cabinet I have 1.5 inches of shims behind it?

Wouldn't that make the countertop look a little funny if it was 1.5 wider at one end than the other, especially if it's only 12 feet?

Thanks all.

  • FYI, tight =/= flush. Flush means "on the same plane as".
    – isherwood
    Feb 12, 2019 at 20:02

2 Answers 2


You want the faces of the cabinets on the same plane, and the entire assembly as close to the wall as can be easily achieved. On average, the wall and the cabinet assembly should be roughly parallel.

If you're dealing with two sets of cabinets at right angles, you'd still want the faces of each set on plane, respectively, but you may not be able to keep a 90 degree included angle.

In this case, your biggest concern is the countertop. A pre-cut 45 degree miter affords you maybe half an inch at the most of scribe-fit depth. You need more than than, which means you'll need your countertop miter pre-cut at a custom angle. That's not a problem if the shop measures in place, but if you're buying tops from a big-box store you're in for a challenge.

Another consideration is how the cabinets align with any relevant patterns in the floor. Diverging lines can make a high-quality installation look shoddy in a hurry.

  • One wall is out of square - it's pitched out such that at 12 feet from the perpendicular wall it's 1.5 inches "out" (not in). So if the two rows of cabinets were perfectly square and I could push them into place as one unit, it would be tight to the wall in the corner and then the 12' end would be 1.5 inches out from the wall. I could just push them all tight to the wall, or do I want them to be perfectly perpendicular? Feb 12, 2019 at 20:42
  • If not '"L" shaped, you put yourcabinets in and use a filler panel in the corner, but your cabinet faces should be flush with eachother. How many cabinets, maybe divide the 1.5" difference between all the cabinets, and stagger themthat difference. a small difference won't be as easily noticed. 6 cabinets would be approximately 1/8 inch staggered. Then your countertop will be slightly crooked, but backsplash flush to the wall.
    – Jeff Cates
    Feb 12, 2019 at 21:39
  • FYI, flush =/= tight. Flush means "on the same plane as". (Is there an echo in here?)
    – isherwood
    Feb 12, 2019 at 21:46

Think of it this way.

When you hang blinds on the outside of a window that has trim, do you pick a spot, get blinds at that spot, and then use a level to finish the install?

The answer is NO! You cannot assume the trim is perfectly level. Your trim slightly off level and then you have blinds at 1" above window on one side and 1.5" above window on the other. Your level is crooked! You simply pick a spot on the trim measure from top or bottom and do the same on the other side, install. Even if out of level it looks level to the eye.

Cabinets are the same. It is about the context not the squareness. In a perfect world yes they should square up. In your case you mount them to wall. If there are two butt walls on each side then you start with one side and modify the side of the last cabinet - I have done this more than a few times.

What will happen if you mount "perpendicular"?

Most people won't notice right away but if looking long at your cabinets they will feel things look weird and a perceptive person might be hit with a moment of squeamishness. Am I drunk or is my depth perception that off? Maybe its me but I notice these things and can notice a 2nd level floor that slopes by 2% by walking on it once. But that isn't the practical reason for installing it wall mounted. That reason is simple, it is far far easier to install the cabinets, plus you won't be relying on some super complex countertop cut that needs to be made. Note that most fabricators come in with lasers and get wall curviture/issues dealt with like that. They do not work so well with floating cabinets. That requires tagging multiple points along your front cabinets. You have to think if you start at one point, you have an overhang and then 5 feet later your counter is 2" wider? Get what I am saying about feeling drunk when looking at your fun house countertops?

  • 1
    That's some wild formatting. Was it intentional? Is this a quiz show? :P I agree, but an out-of-perpendicular corner requires a custom countertop cut. A standard 45 degree miter won't work.
    – isherwood
    Feb 12, 2019 at 20:49
  • @isherwood - take cabinet apart until you can get everything cut with a circular saw. Often this is just removing side and face plate. If the wall is drywalled it is even easier as you basically have a half inch of leeway - not saying to be off by that but sure helps when you are 1/8" off on an angle to just strip a little drywall out. On countertops really the only custom cutting is if you do have a butt wall or wall curviture. If a butt wall is there it is just an angle for that at the end - not having a possible 30" wide counter turn slowly into 32". That is not normal variance.
    – DMoore
    Feb 12, 2019 at 21:47

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