UITextView *textview = [[UITextView alloc] initWithFrame:CGRectMake(42, 150, 440, 60)];

CGFloat w = [UIScreen mainScreen].bounds.size.width;
CGFloat h = [UIScreen mainScreen].bounds.size.height;
// Do something like this if you can
UITextView *textview = [[UITextView alloc]
    initWithFrame:CGRectMake(w*0.025, h*0.25, w*0.5, h*0.125)
];