Based on @MichaelCrawford answer, if AdobePoint = 1/72 of inch then we could calculate transition formula to ApplePoints.
What we need to know is:
- Photoshop file resolution (px/inch) - Res
- Photoshop mockup size, i.e for what iPhone factor it's created like @2x, @3x - Factor
- Photoshop text size in AdobePoints - PSFont
Then, as I understand, you can calculate iPhone Font size (that actually equals iPhone points), like this
iPhoneFontSize = (Res / 72 ) * PSFont / Factor
Example:
You have mockup for iPhone 5, but all media also good for iPhone6+, then mockup size is iPhone 5 size * 3 = 960x1704, resolution is 401 (for iPhone6+). TabBar title font size on this mockup is 5 pt
Therefore, on iPhone you should setup size as 401 / 72 * 5 / 3 = 9.28
If resolution of file is 72 (for Web), you just need to divide PSFontSize to factor as you usually do to calculate control or imageView size.