Best way is to take you OG before fermentation. After the cider has completed fermenting, take another gravity reading, this is your FG. Take the OG and minus the FG from it. Then take the total and times it by 131.25 and you'll get your ABV.
Edit: just saw your reply after I posted. To me it seems your still high in the gravity area. Your FG should be way lower.
In the Works: Peach Berry Wheat Ale
Conditioning: Blue Moon Clone, Double O' Blossom Honey Hefeweizen
In the Fridge:Blind Pig IPA, Raspberry Wheat Ale, Capt. Cascade American Amber Ale
Primary #1: Carmel Apple Cider 4 weeks on 01/16/13 Primary #2: Spiced Apple Cider 2 weeks on 01/17/13