What memory is equivalent to 256 iphone11

For that type of comparison, an iPhone 11 takes photos that are about 2-3 MB in size.

An iPhone 14 or 15 Pro is about 30 MB for a 24 MP image, and 75 MB for a 48 MP image. This assuming you're shooting Pro RAW, which results in a DMG image. HEIC images are a lot smaller. 3MB for a 24 MP image, and 5 MB for a 48 MP image.

If you tend to shoot RAW images (as I do), and you do a lot of shooting, you'd fill up a 256 MB phone pretty fast. But that depends on how many pictures you take per day, and if you move them off the phone to other storage at the end of each day, or as the phone is getting full.

Let's presume you mean you're going to purchase a 15 Max Pro since an iPhone 16 does not yet exist.

Equivalent would literally be 256 MB. But you can also order double the storage space with a 512 MB version, or quadruple the space with a 1 TB version.