iOS navigation bar item image size
These are the sizes that the documentation recommends for custom icons now.
- @2: 50 x 50
- @3: 75 x 75
Create two images of the above pixel sizes and then add them to a new image set in your Assets.xcassets file. (Apparently the @1 size is no longer needed.)
Alternatively, you could use a universal vector image (pdf) (see here and here). This has been my preference recently.
Related answer
Apple updated their Human Interface Guidelines Docs. Now the recommended sizes for creating custom icons for Navigation Bar and Toolbar
@2x -
48px × 48px(24pt × 24pt @2x)@3x -
72px × 72px(24pt × 24pt @3x)
The typical standard sizes (non-Retina) are 22px by 22px, while the 2x (or Retina) sizes are 44px by 44px.