Sizing Cloud Backups with Vendors

[thevikingman]

Let's say that you have 5TB of data to back up in total. So you seed that to a cloud connect vendor...
Then lets say you want some retention policies like "be able to restore files on this server and that server for 2 years back" etc.
Does having a retention policy like this cause the backup size to be a lot more than 5TB in the cloud?

Also lets say you do incremental backup each day and send that off, and then you do a full backup once a week and send that off.
Does the 5TB grow a lot larger or does it stay around the same? I would hope that the full backups just overwrite what the last one was?
Just trying to figure out a solution where if I sign up for X per month and then do a few weeks of backups it doesn't suddenly grow to be a huge bill.
I do understand if I add servers or data in general to the environment locally then that means the total size will increase, but I'm not clear on if things mostly are the same locally for a while, but yet I'm doing long term retention and full backups each week, how the affect would be.

[veremin]

This tool might help you to get approximate backup chain size. Thanks.