If you mean specifically Lego bricks, I'm pretty sure the 1x16 was/is the longest one made. Outside of the 1x? sized bricks, the longest plain shaped brick that I know of is part #30072 or #47122 at 24 studs long. I don't know about other brands though.
Interesting related post:
What is the largest single LEGO piece?
I assume you mean L when you say units?
Well anyhow, unless im misunderstanding, I would try these: https://www.bricklink.com/v2/catalog/catalogitem.page?P=6575
You can stack 3 of them up to get 1 and a half L
If you mean 3L long instead of wide however this should still work because it has an axle hole which is 1.5 apart, it also has axle holes that are ...
What a tricky (bricky!) question.
So, can one estimate the number of bricks in a bag or box by weight?
In fact, they do weigh bags and boxes over at the factory to make sure there aren't any parts missing. But of course they're just comparing expected weights.
That's why you can't simply weigh a big mix of unknown bricks to
Outer (hub): 6.8 mm/.268 in./ 17/64 in.
Inner (shaft): 4.9 mm/ .193 in./ 25/128 in.
Teeth (key): 3.32 mm/ .1305 in./ 17/128 in.
-These are close/approximate, not exact due to the tolerances and/or wear. I measured 4 different gears with a digital caliper and the measurements were all within .10 mm of the listed measurements. The measurements even varied ...
This is marketing department wizardry.
From a pure engineering point of view, the closer to a perfect cube (or rather sphere) you are, the greater of internal volume you can enclose with the same amount of material.
What does this mean? By not making cube shaped lego boxes, Lego isn't trying to be as efficient as they can be when it comes to their box ...
No restrictions on the materials.
Well then, probably a component to the old wooden furniture LEGO used to produce, like these:
5003483 - 3-Seat Playtable Creative Play Station Center Pack Duplo
Or the similarly designed 4509g - 3-Seat Playtable, 5004063 - 3-Seat Playtable, or 5003468 - 3-Seat Playtable Creative Play Station Center Pack.
IF-LTW2C - ...
If the parts came from sets then you can search bricklink.com for the sets, and it will then tell you how many parts is in each set. It is then just a matter of summing them up.
If the parts are not part of a set then im afraid there is no easy way to do that, especically if the parts are quite varied.
Magnus' answer doesn't explain why different themes have same sized boxes or same front area (but different depth). Also same set re-release can have different sized box (take Mini from Creator for example). So there doesn't seem to be a rule for that.
What I heard from TLG employee is that front area of the box is basically a marketing space. So TLG tend ...
The size of the box seems to be theme specific.
It appears that they choose a specific box design for any given price range and then stick to that size for the rest of the theme. For example, in the pictures below, you can see same sized boxes used in the same themes.
There is definitely some crossover, but for the most part this holds true.