I realize without knowing my abilities, that no one can really say.
Exactly. If you don't know yourself, no one here can tell you how much you'll want to carry. Crunch numbers all you want but the only real answer comes from trial and error. There is no substitute for personal experience.
I will add this: A properly fitted pack will make your load FEEL
lighter and an ill fitted pack will make your load feel heavier. Also, weigh your pack before every trip. Don't guess. Then you'll know exactly what you're dealing with.