Person Account conversion data size consideration

Question

my company is scoping the possibility of enabling person accounts. I have been reading through documentation and different blogs to get a feel for pros and cons of doing this. One thing I found that I am not sure how to interpret - record sizes. If we are talking about converting existing Contact into Person Account, that means that a new Account record will be created, and it will be linked to the 'old' contact record with 1-1 relationship. So the Contact record stays, it will just be hidden from users. Now given relative sizes for records:

Contacts -- 2KB

Accounts -- 2KB

Person Accounts - 4KB

If for example we have 14 million Contact records it is roughly 24 gigs of storage. Now if we convert 3M of those into Person Accounts, does it mean that we will need 12 additional gigs of data storage(since 3M*4KB = 12 Gigs) or will it be just 6 Gigs (since we already have Contacts data in the system and we are just creating additional 3M Account records for those converted Contacts)?

Answer 1

See the Salesforce Knowledge Article you linked which is now updated: Salesforce record size overview

Person Accounts consume roughly 4KB. They are a junction of two individual records, an Account and a Contact. For example, 500,000 Person Accounts will require around 2GB of storage

You'll just need the 6 Gigs.

From my understanding of working with Person Accounts, Person Account records are just the combination of an account and contact record: they even maintain their separate Ids - PersonContactId. See the section on IsPersonAccount Fields: Account Object Reference See another answer mentioning the same: ID for Contact portion of Person Account

To further clarify, that a single person account record is just one contact and one account record, both records are updated when a Person Account is updated, see Updating a Person Account.

Now, how you go about turning those 3 million contacts into person accounts, you should follow the guide (create matching business accounts for each contact, then perform a mass update): Change business accounts to person accounts