I was looking at an issue really close to your problem for my own work just a few days ago.
The call you're looking for (which will solve your ultimate problem) is "boundingRectWithSize: options: attributes: context:
", where you pass in the UIFont you loaded (from your TTF file) as one of the attributes.
Even better, use a NSAttributedString or NSMutableAttributedString (which also has a "boundingRectWithSize: options: context:
" method, because then you can calculate your text width and height with a mix of fonts and font styles.