When looking at modern car radios, it's obvious that the vast majority of these has 6 buttons for pre-set radio stations.


Why not less, why not more?

It was very tempting to add the tag to this question.

  • This could be relative to memory span (a short-term memory function), to avoid drivers to think too much about the station they're looking for or spend too much time on the buttons. This memory span is supposed to be 7 elements (plus / minus 2).
    – Brice
    Commented Jul 19, 2016 at 8:52
  • @Brice possibly, although the buttons often have a pre-set for each band, often even with 2 FM-bands. Another possibility is that the buttons (used to) double for operating a cassette, 8-track, or CD player (play, fast-forward, rewind, pause, stop, eject), but that's just speculation.
    – SQB
    Commented Jul 19, 2016 at 9:00
  • 1
    Because mechanically and logically 6 is a great number. According to the user research, it was found that on an average people have 6 favourite channels and mechanically if you place a button of size 1 inch each then 6 buttons can be placed easily but if you have 40 favourite buttons then it will cost 60% of your dashboard and while driving it is easier to chose amongst the 6 buttons(specially on the bumpy road). There was a discussion at reddit you can refer that too.
    – Sanshizm
    Commented Jul 19, 2016 at 9:02
  • @SQB Why not, but most of car radios now have this functions on other buttons.
    – Brice
    Commented Jul 19, 2016 at 9:02

3 Answers 3


The cut out of a radio is a standard size. Slightly wider than a finger is about 6 buttons. In the old day the manual button really moved a dial.


I like the 6 CD changer idea: my car has a 6 CD auto changer in the boot.

Its also possible that its just a 'carry over' from the design of mechanical buttons for pre-sets. The design pattern has continued even when the original technological constraint has vanished.


The answer is to do with 'Subitizing' - identifying quantities at a glance rather than counting.

Most people can easily identify six items if ordered (e.g. in a row as the buttons are - or as two rows on a dice face).

Seven buttons would make it too tricky to locate a station.

Obviously 1-5 are also fine, but fewer buttons mean less stations.

  • One button - LOL
    – user67695
    Commented Nov 22, 2017 at 17:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.