How to center content in a UIScrollView with contentOffset

I think you want:

CGFloat newContentOffsetX = (self.contentSize.width/2) - (self.bounds.size.width/2);

diagram:

|------------------------self.contentSize.width------------------------|
                         |-----self.width-----|
|-------- offset --------|
                                    ^ center

Use below code:

CGFloat newContentOffsetX = (scrollView.contentSize.width - scrollView.frame.size.width) / 2;
scrollView.contentOffset = CGPointMake(newContentOffsetX, 0);

Swift 4

Scroll to center of content of ScrollView

let centerOffsetX = (scrollView.contentSize.width - scrollView.frame.size.width) / 2
let centerOffsetY = (scrollView.contentSize.height - scrollView.frame.size.height) / 2
let centerPoint = CGPoint(x: centerOffsetX, y: centerOffsetY)
scrollView.setContentOffset(centerPoint, animated: true)