Well with 5 gallons of fresh pressed Cider, my starting gravity is usually around 1.045 and finishes at around 0.009, putting it at about 4.8%. So with 2.5 gallons of juice over a lb of table sugar, I am guessing you'd be slightly higher than that for 3 gallons. You may need to back sweeten, but wait and time will tell.
Event Horizon ~ A tribute to the miracle of fermentation.
Brew what you like. Do this, and you will find your inner brewer.