How can I calculate the Churned Subscribers number in the Subscribers Analytics dashboard?

A subscriber is considered "churned" if they had a subscription(s) previously but now all subscriptions have expired.

1. Download the Subscriptions export (All: Subscription status, Time Range: All Time)
2. Once downloaded, go to the account code column and check for duplicates. You will have to go through the list of duplicates to see if any of the accounts with subscriptions that have a State of Expired also have any active or canceled subscriptions also. If they do, this means they would NOT be counted as Churned Subscribers since they still have other active subscriptions on the account. If they don't, this means that this account WOULD count toward the Churned Subscribers metric since all subscriptions on that account are expired. 
3. Once you have gone through the duplicate accounts, you can use the expires_at column to only show the time range that you are analyzing. For example, if you're looking at churned subscribers for February, you'd filter out anything outside of February 1-February 29, 2020 for this column.  You can then save your totals and remove them from the list. 
4. From the remaining the list, you would want to go to the State column and remove all states except Expired. This would leave you with a list of churned subscriptions that were the only subscriptions on the account and therefore all of them would count toward the Churned Subscriber metric. Again, you'd then use the expires_at column to remove all dates outside of the time range you are analyzing. 

Note: Analytics undergoes a series of complex transformations and can't cover all scenarios for all customers. In that light, the numbers extracted from the API and automated exports should be considered the truth