The Expected Revenue figures displayed on the Dashboard (for live sites only) can be calculated using the following formula:

(Payments of this month* - refunds of this month**) + ***subscription's next_billing_amount 

*Payments of this month are calculated by navigating to Logs->Transactions->and use the filter Transaction date = this month

**Refunds of this month are calculated by navigating to Logs->Transactions->and use the filter Transaction Type is Refund and Transaction Date is This Month.

***Subscription’s Next Billing Amount= Navigate to the Subscriptions Page and use the filter Next Billing Date is between 1st to today and Status is Active.

Note:
The calculation can also be configured to include trial_and_future_with_card = true
For this, the calculation above shall also include subscriptions which are in trial and are going to be upgraded this month while it should have a card added on file.
To do this, change the Subscription’s Next Billing Amount filter to include status - In Trial and Future and Payment Method Type is Card.