Next backup size is always WAY lower than the actual. So I can't backup because I don't have enough iCloud space and it doesn't give me any other option to reduce the size.

Hello wilef,

Thanks for following up.

In regards to turning iMessage off, this would place your message history within the iCloud backup as opposed to storing within iCloud to sync your messages across all devices. For additional information on this, check out the following resource where the information below is also found: Use Messages in iCloud - Apple Support

If you turn off Messages in iCloud on an iPhone, iPad, or iPod touch, your message history will be included in iCloud Backup. If you set up an Apple Watch for a family member, Messages in iCloud is the only way to back up messages.

As for the Next Backup Size question, you would be adding this to what is currently stored with iCloud already as this is adding new information that isn't backed up yet. If this were to replace the total Backup Size to what is shown in Next Backup Size, that would entail removing what is currently stored as a backup and replaced with the lesser amount; therefore, causing you to lose information. We hope that's able to help understand this better.

Have a great day!

Hey there, wilef.

You could try restarting your device to see if that might help refresh the storage amounts showing for you: Restart your iPhone - Apple Support If a restart shows the same amount after that and if you've tried managing the storage as much as possible for iCloud, you can contact Apple Support for further assistance here: Contact Apple Support

Best wishes.

Hi wilef,

We'll be happy to help out with understanding the Backup information you are seeing when you are looking at Backup Size and Next Backup Size.

Backup Size, you are correct, that is your current amount of iCloud storage that is being used as of the last iCloud back up that was performed.

Next Backup Size, this is the amount of storage that will be needed to add to your current Backup Size. It doesn't replace the Backup Size.

If you are needing to clear up space so you can back up to iCloud, take a look at the this link, Manage your iCloud storage. It gives you suggestions on how to free up storage.

Reach back out if you have any questions.

Cheers!

wilef,

Thanks for getting back to us. It is simple mathematics. You have a set about of iCloud storage and a set size of data to be backed up from your iPhone. If the iCloud storage is too small for the backup, you will have to increase the available iCloud storage either by purchasing more space or reducing the amount of information stored in iCloud. Or you can reduce the data being backed up from the iPhone.

You can take a look at this article for suggestions to address iCloud storage: If you can't back up to iCloud - Apple Support

You can take a look at this YouTube video to free up space on your iPhone: How to free up space on your iPhone, iPad, or iPod touch - Apple Support

Regards.