What the item count actually counts
Scroll to the bottom of the grid and iOS prints a number of items. It is worth knowing what that word covers, because people quote it as if it described the size of their library:
- Photos and videos together. One 4K video counts as one item and can outweigh hundreds of photos.
- A Live Photo counts as one item, although it stores a still and a video clip.
- Screenshots and images saved from other apps count exactly the same as a photograph you framed and took.
Which is why two people with the same item count can be tens of gigabytes apart. The count tells you how many decisions are waiting; it tells you almost nothing about the space.
How to get your own real number
Two readings, one division:
- The item count at the bottom of Photos › Library › All Photos.
- The Photos row in Settings › General › iPhone Storage.
Divide the second by the first and you have your true average per item — better than any estimate, including ours. If it comes out far above a couple of megabytes, the usual reasons are video in the count, Live Photo on every still, and bursts. The storage calculator works the same sum in the other direction.
Why it fills with things you never took
Because saving to the library is the default behaviour for most apps that touch an image. Messaging apps can auto-save every picture you are sent, and anything you download or screenshot lands in the same grid as your holiday. Over a few years that traffic can outnumber your own photographs.
Kept sorts the whole library on the phone — your own shots and everything that arrived by itself — and every delete goes to Apple’s Recently Deleted, recoverable for 30 days.