Universal App - size of UIModalPresentationFormSheet

[Matic]

Hello,

i am making a universal app and I would like to use same View (XIB) and ViewController for iPhone and iPad. However, I need to get the size of UIView in ModalPresentation Controller in viewDidLoad on iPad.
If I try with: self.view.frame.size.width; I always get 320 (iPhone version) but obviously ModalView on iPad is bigger. How can I get the size of ModalViewController on iPad in code?

Thanks!