I scrubbed up an old excel calcutor that some people might find interesting when dealing with deduplication for storage and data transmission between storage devices including cloud(s).
Other caculators are avaliable that are backup/recovery centic and will give the amount of storage required that can be feed into this one. Given the prevalence of dedupe most people have a reasonable idea how much can be saved but they usually not aware what happens if the dedupe rate changes.
The idea of this calculator to highlight how sensitive data stoage and transmission is to dedpulication efficiciency and less so to other metrics. < more here + download link>