You're looking to calculate the amount of sugar in your beer? Measure in Plato, that gives you the percentage of sugar, approximately, in the solution. If you have 100 grams of solution at 10 Plato, about 10% of the solution, or 10 grams, are sugar. If you're using Specific Gravity, you have to use points. Multiply the last three digits following the decimal point by the volume you have it, example, 5 gallons of a 1.050 beer has 50*5, or 250 points of sugar. I'm going to work in conventional units but the math works the same for metric, you'll be using points per kilogram per liter. After doing the calculation above, you have the points of sugar in the solution. Pure sugar is 46 points per pound per gallon. So divide the number of points by 46 and you have pounds. If you want pounds/gallon, divide the pounds by the volume.
