I suggest that most purposes eg. El Reg login, an 8 character password is sufficient, provided it is based on an uncommon pattern involving mixed alphanumeric and symbol characters
You're just so much better off with a nice long passphrase. Four random words, slightly randomized variations of their spelling, capitalization, spacing, etc., and you're extremely secure, with no more effort than memorizing a super complex string of random characters. The only valid excuse I've seen for short passwords is cumbersome input devices on phones and the like.