Sorry, didn’t answer before.
About 70± regular single-sleeve LPs per cubicle. About 30 gatefolds (like the Music Matters Jazz, Tone Poet, MoFi variety). That’s with wrapping all my albums in 5mil outer sleeves, so that’s probably an extra few widths of an LP per 50.
Just in case no one has replied and warned you… rotate by 90 degrees. You are using the uprights as shelves; the shelf is the longest piece.
Same with yours; the square ones are on their sides.
Here the shelf is supported by the uprights in the middle, as well as the dowels left and right.
It’s radical. But sometimes folks do things differently, for various good reasons 
Great thanks. My new room will be ready end November and glad to have found a good and relatively cheap place for all my vinyl. It looks like the frame to hold the shelves needs the unit to be rotated by 90 deg which means the long shelves will be vertical. Better if they were horizontal so they are supported by the vertical “shelves” if that makes sense. Could be that I don’t use the frame in the end
Bear in mind that Kallax doesn’t come with a back board, so if you wanted to strengthen a non-visible side, you can simply cut a piece of board and screw on, to improve structural rigidity etc,
Oops, never spotted that, just checked IKEA’s website and you are right - although the whole thing is very stable but I will change it - many thanks 
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Peter
If you don’t change to correct orientation it will eventually lose structural integrity and collapse. See pictures upthread.
Bit of a stretch to say it will happen. Might would be a better term. I would imagine it depends on a number of things, including how many LPs are in each compartment
The 2x can go in any orientation. Even Ikea has legs you can put on the 2x4 in horizontal orientation.
It’s the 4x4, 5x5 that have to be oriented with the long pieces as shelves and short pieces as shelf supports/walls.
Assume it will happen and avoid crying about it I say.
True. Didn’t realise it was not a problem with the 4 by 2 which I have. Makes sense it is more of an issue with the bigger stuff
Yeah, if you look at my Ikea in the photo above you’ll see I have a 2x4 on top of my 4x4. I know it seems precarious, but it’s been like – packed full of records – that since I built it Dec. 2015. I suppose worst case scenario if mine collapses it only has a half foot to the right and about a foot to the left to fall over before it hits solid walls (plaster on lathe and plaster on brick). However, I see no evidence of weakness or lack of sturdiness, and I am moving/reorganizing records around on those shelves all the time.
It’s still stronger with the long pieces horizontal; simple physics, supported in 3 places. Those little dowels can fail if that’s all that’s supporting a section full of vinyl, or more likely, the shelf itself would split where the dowels are inserted. The square pieces are uprights.
Yeah, I get it. I’ve been doing this for a long time. See my posts above. Yes, orientation matters for 3x, 4x and 5x. I agree that a 2x in the vertical orientation is stronger, but for the 2x4 it just doesn’t really matter. It’s just one internal shelf, not 3 or 4. I’ve been putting 2x4 in horizontal orientation for years, filled to the brim, and never had a single failure, not one. OTOH: I would never mis-orient the shelves that are greater than 2x. That’s too risky.
And here’s is Ikea’s own product page showing a 2x4 used in horizontal orientation, exactly as I use them for my record shelves. Either way is fine with this unit, even full of LPs.
Ikea even shows a mis-oriented 3x4 with the footed base on their product pages, but I would not use it that way to store records.
Although, when we use these shelves for records we are exceeding the 29 lb. max load per shelf. Nevertheless, after some 13 years using Kallax – and the predecessor Expidit – these have performed brilliantly for me. I now have three 4x4, three 2x4 and two 2x2 Kallazx in gloss white, all loaded with records, except one that is used for accessories, manuals and my Degritter.
Old fashioned single albums, perhaps up to 70 (but a bit tight).
Modern album sleeves seem bulkier, so I’d suggest 60.
I just counted one shelf of my shelves - and got 86 records - counting a Double LP as 2.
A big squeeze? Do you use poly outers?
No - just right. No poly outers.
A bit less ‘tight’ thanks to several sales on Discogs. LP’s seem to sell quite well, while CD’s just don’t.
