Alcohol content in your beer or wine can be measured easily with this one simple tool that should be in every beer or wine makers toolbox. To use, you will need to record your original gravity before fermentation begins. Once fermentation is complete you will need to take another hydrometer reading. With these two numbers you can find the approximate percent ABV. There are many calculators you can use online to compute your products alcohol content with these numbers or you can use the formula below. (Original Gravity - Final Gravity) x 131.25 = ABV% S.G. Scale Of 0.98-1.160, Potential Abv Scale 0-16%, Sugar Per Liter Scale 0-34.