iCloud Backup: inconsistent sizes

Is it just me or do others also see wide variations in what should be the same figure?

This is on my 12 mini running 16.3.1.

Settings > iCloud > iCloud Backup says 1.3 GB.
Settings > iCloud > iCloud Backup > Device says 1.4 GB.
Settings > iCloud > iCloud Backup > Device totaling individual contributions results in 1.1 GB.
Settings > iCloud > iCloud Backup > Device > Next backup says +630 MB.
Next backup actually adds 100-160 MB depending on which of the above you believe. Immediately thereafter:
Settings > iCloud > iCloud Backup > Device > Next backup says +14.3 MB.

??? :confused:

Not just you. On my 13 Pro Max, iOS 16.3.1, the sizes for the categories you listed are similarly inconsistent.

I stopped expecting consistent, deterministic information about storage usage from Apple somewhere around the release of High Sierra and APFS. Howard Oakley had an article about the challenges of measuring available storage on Macs fairly recently over at https://eclecticlight.co/, though I can’t find the link at the moment. Nowadays, I just make sure that I have qualitatively “ample” storage space on all of my devices and on iCloud. Defining “ample” can be challenging. On modern Macs, I try to keep a minimum of 10% of the nominal capacity free and to avoid going below 50 GB free even on systems with 256 GB SSDs.

This is not about storage on your iPhone. It’s about how much your iPhone backs up to iCloud. That should be known down to the MB. Apple displays that information in at least 3 different locations and not a single one of them is in agreement. :man_facepalming:

Welcome to Apple’s brave new world, where their response is more “You don’t need to know” than “Here is the information you seek.”