48
Remnants power armor + helmet is 36
Toughness perks + the Subdermal implant is 10
Last two must be from OWB, I forget.
But it is 48. Though of course you can get it higher by using Esther or drinking alcohol with Cass around or taking a perk like Hit the Deck. With those temp/conditional buffs, you could get over 100. (But you ARE restricted to only wielding Esther or you lose it)
EDIT: I just realized I read it wrong.
And it'd be 10-12 if we're talking NO armor. Reason I say 10-12 is because the OWB DT perks can be a little odd and give 1 or 1.6 or the like, though they CAN give 2. But Toughness + Subdermal is 10.