You don't have to calculate how far to shift everything down, there's a build in property for this. In Interface Builder, highlight your view controller, and then navigate to the attributes inspector. Here you'll see some check boxes next to the words "Extend Edges". As you can see, in the first screenshot, the default selection is for content to appear under top and bottom bars, but not under opaque bars, which is why setting the bar style to not translucent worked for you.

As you can somewhat see in the first screenshot, there are two UI elements hiding below the navigation bar. (I've enabled wireframes in IB to illustrate this) These elements, a UIButton and a UISegmentedControl both have their "y" origin set to zero, and the view controller is set to allow content below the top bar.

This second screenshot shows what happens when you deselect the "Under Top Bars" check box. As you can see, the view controllers view has been shifted down appropriately for its y origin to be right underneath the navigation bar.

This can also be accomplished programmatically through the usage of -[UIViewController edgesForExtendedLayout]. Here's a link to the class reference for edgeForExtendedLayout, and forUIRectEdge

[self setEdgesForExtendedLayout:UIRectEdgeNone];

I created my view programmatically and this ended up working for me:

-(void) viewDidLayoutSubviews {// only works for iOS 7+if([[[UIDevice currentDevice] systemVersion] floatValue]>=7.0){CGRect viewBounds =self.view.bounds;CGFloat topBarOffset =self.topLayoutGuide.length;// snaps the view under the status bar (iOS 6 style)
        viewBounds.origin.y = topBarOffset *-1;// shrink the bounds of your view to compensate for the offset
        viewBounds.size.height = viewBounds.size.height +(topBarOffset *-1);self.view.bounds = viewBounds;}}

Source (in topLayoutGuide section at bottom of pg.39).

If you want the view to have the translucent nav bar (which is kind of nice) you have to setup a contentInset or similar.

Here is how I do it:

// Check if we are running on ios7if([[[[UIDevice currentDevice] systemVersion] componentsSeparatedByString:@"."][0] intValue]>=7){CGRect statusBarViewRect =[[UIApplication sharedApplication] statusBarFrame];float heightPadding = statusBarViewRect.size.height+self.navigationController.navigationBar.frame.size.height;

      myContentView.contentInset =UIEdgeInsetsMake(heightPadding,0.0,0.0,0.0);}

In your apps plist file add a row call it "View controller-based status bar appearance" and set it to NO

The simplest trick is to open the NIB file and do these two simple steps:

1. Just togle that and set it to the one you prefer.

1. Select those UIView's/UIIMageView's/... that you want to be moved down. In my case only the logo was overlapped an I've set the delta to +15; (OR -15 if you chose iOS7 in step 1)

And THE RESULT:

edgesForExtendedLayout does the trick for iOS 7. However, if you build the app across iOS 7 SDK and deploy it in iOS 6, the navigation bar appears translucent and the views go beneath it. So, to fix it for both iOS 7 as well as for iOS 6 do this:

self.navigationController.navigationBar.barStyle =UIBarStyleBlackOpaque;if([self respondsToSelector:@selector(edgesForExtendedLayout)])self.edgesForExtendedLayout =UIRectEdgeNone;// iOS 7 specific

add the key View Controller-based status bar appearance from the dropdownlist as a row ininfo.plist something like this : 

I would like to expand on Stunner's answer and add an if statement to check if it is iOS-7 because when I tested in iOS-6 my app would crash.

The addition would be adding: 
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0)

So I would suggest adding this method to your MyViewControler.m file:

-(void) viewDidLayoutSubviews {if([[[UIDevice currentDevice] systemVersion] floatValue]>=7.0){CGRect viewBounds =self.view.bounds;CGFloat topBarOffset =self.topLayoutGuide.length;
        viewBounds.origin.y = topBarOffset *-1;self.view.bounds = viewBounds;}}

To me, the simplest solution is to add two keys into the plist

I have a scenario where I use the BannerViewController written by Apple to display my ads and a ScrollViewController embedded in the BannerViewController.

To prevent the navigation bar from hiding my content, I had to make two changes.

1) Modify BannerViewController.m

-(void)viewDidLoad
{[super viewDidLoad];float systemVersion =[[[UIDevice currentDevice] systemVersion] floatValue];if(systemVersion >=7.0){self.edgesForExtendedLayout =UIRectEdgeNone;}}

2) Modify my ScrollViewContoller

-(void)viewDidLoad
{[super viewDidLoad];float systemVersion =[[[UIDevice currentDevice] systemVersion] floatValue];if(systemVersion >=7.0){self.edgesForExtendedLayout =UIRectEdgeBottom;}}

Now the ads show up correctly at the bottom of the view instead of being covered by the Navigation bar and the content on the top is not cut off.