Welcome, Ryan.
You need to determine whether the basement wall is capable of acting as a support for your joist system above and thereby effectively reducing the unsupported span.
You need to consider what the wall is sitting on, whether the studs are directly under the joists or that you have a doubled top plate, whether the top plate is actually making contact with each joist to provide support, whether the wall is sheathed on at least one side, etc.
If it's a support wall, you measure the longest unsupported joist span with that in mind and enter that figure into the Deflecto.
My opinion; worth price charged.