FontSize vs Device

I’m trying to figure out “real world” visual attributes, using only the iOS Simulator (obviously real devices are physically smaller)

If I display some text on an iPhone5 ( device is 320 pts wide), and I use fontsize of 8.00 , this I can see as I own an iPod touch
now on say an iPhone6s (375 pts wide) does a smaller font (say 7.50 instead of 8) have the same readability as the iPhone5s did?

my logic (which may be flawed) is [using a monospaced font]

iPhone 5 :

  • fontsize 8.00
  • 80 character long line is 308.25 points wide
  • extrapolated would be 66.5 characters per line
  • screen size (3.50" / 66.5) = 1 char ~ 0.0526" wide

iPhone 6 :

  • fontsize 7.50
  • 80 character long line is 361.23 points wide
  • extrapolated would be 83 characters per line
  • screen size (4.70" / 83) = 1 char ~ 0.0566" wide

iPhone6 would have a character roughly 7.5% larger? (I’m talking PHYSICALLY, not point or pixel wise)

So if this is correct… on an iPhone6 even with a slightly smaller fontsize, I can display 80 characters at almost the same readability as 64 characters on an iPhone5