Personal Capital will remind you of bills due for: credit cards, loans and mortgages. You need to first add those accounts using the LINK option at the top of the My Accounts panel on the left.
For Credit Cards the amount due varies by the credit card. Most credit card issuers list the amount due as the minimum amount due on the account. If you expand the bill details from the Bills page, you can see the Statement Balance, Minimum Due. The Statement Balance is generally the total amount of the credit card bill.