On a full boil, I usually start with about 7-7.25 gallons and end up with about 6 gallons. 6 gallons because I then transfer 5.5 to the fermentor and then keg/bottle 5 gallons on the button. So, yes totally normal to boil off a good bit.
Draft 1: Lightly smoked Weizen
Draft 2: Belgian Wit
Draft 3: Rauchbier
Primary 1: German Scwarzbier
On Deck: Belgian Brown Ale, Pale Ale, Stout