According to this article, it states

Placing options in a selector drop-down requires two clicks, and hides the options. Use an input selector if there are over 5 options.

enter image description here Why the magic number 5? Why not 6,7, or 8?

Please write answers explaining the cases when the 5 works and when it does NOT.

  • Read the same article. It's probably not a hard-and-fast rule but more of a guide. 6 or more seems like a lot to fit on mobile too. Really easy to fat-finger at that point. Dec 9, 2016 at 4:01
  • 1
    Five is about the number of items a person can evaluate in a glance – that may be part of the reason. See "subitizing." Dec 9, 2016 at 4:26

2 Answers 2


It's because of one of the vital UX Law called as Miller's Law.

George Armitage Miller (Princeton Professor and Cognitive Psychologist) formulated a law based on his observations and findings in his the theory of communication, which states that :

The number of objects an average human can hold in working memory at a single glance is 7 ± 2.

Which means, normal people can only be able to keep five to nine items in their short-term memory before they forgot or had errors.

So, for better accessibilities and compatibilities it is always advisable to present 5 i.e. (7-2) objects in front of the users. This law both assist in the usability / experience of design as well as the aesthetic values. Henceforth, the magic number is 5.

But be informed that there are variety of cases where Miller's law has been used to justify limiting number of items in an interface or Display.

For example:

  • Navigation Menus
  • Number of tabs
  • Number of fields in a form
  • Number of action links, etc.
  • 3
    While this may well be why we historically ended up at five, nowadays this is generally considered to be a mis-application of Miller's Law. Miller himself has said "The point was that 7 was a limit for the discrimination of unidimensional stimuli (pitches, loudness, brightness, etc.) and also a limit for immediate recall, neither of which has anything to do with a person’s capacity to comprehend printed text.”
    – calum_b
    Dec 9, 2016 at 16:46
  • Agreed. It's an example of quoting a "bottom line result" without appreciating the specific context that that result was derived from.
    – PhillipW
    Dec 9, 2016 at 23:30
  • I second your thoughts @scottishwildcat and Mr. PhillipW. It was just an answer to the question : From where that magic number 5 came from? Indeed, it was deceptively interpreted but the designers are using that “bottom line result” in right context which has proven to be very effective in design and aesthetics. Though, it’s being said that laws are just for a reference, creativity and inventiveness stands first in every design context. We are free to explore, invent and create. Dec 12, 2016 at 8:58

The easiest way to understand this is to think in terms of the simplest visual patterns of groupings, in which 5 is a magic number, because everything in a list of 5 has a perfectly describable and consciously recognisable place.

Let me try to use words to demonstrate this, and imagine vertical, though horizontal is much the same.

Each position is perfectly mentally understood as either:

Top, bottom, middle


Next to top and above middle


Next to bottom and below middle

This makes 5 objects the largest list of absolute positions instantly identifiable and classifiable by the viewer.

Got 6 items, there is no middle. A huge loss of reference.

At 7 items there are two objects between the top and the middle, the middle and the bottom. Much ambiguity.

Even 4 numbers is less preferable because the middle two objects are muddied in mental descriptiveness by the lack of a true middle.

Hence the magic of a list of five.

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