Every record takes up the exact same storage based on its type. For most recordsFor most records, this is 2kb per record. If you erase every single field value, but don't delete the record itself, it will still use the same 2kb. Note that each type of record uses storage. A contact with 100 cases uses a total of 204kb, 200kb for the cases, 2kb for the contact, and 2kb for the account. Also note that files use separate storage, and is 1:1 with regards to the size of the file.