How do I tell what the capacity for the Staging Area is?

When you click on the staging area you see 2 numbers, the first is the unit storage amount in the staging area on your base, the second is the current max capacity for your staging area. When you view the staging area popup, via the units button or the staging area you see the max capacity again, but also a figure that includes the totals for the storage for units on your base plus units in your platoon plus any units you have at Deposits.