Instructions

1. Find the measurements of each of the drink's ingredients listed in its recipe. For an example, the mixed drink is a white Russian, and the recipe calls for 1 ounce of vodka, 1 ounce of coffee liqueur and 2 ounces of cream.

2. Find the proofs of each alcoholic ingredient. The proof is a liquor's alcoholic measurement and is located on its label. For this example, the vodka has a proof of 80 and the coffee liqueur has a proof of 40.

3. Divide each liquor's proof in half to calculate that liquor's ABV. For this example, half of the vodka's proof of 80 is 40 and half of the coffee liqueur's proof of 40 is 20. The vodka has an ABV of 40 percent and the coffee liqueur's ABV is 20 percent.

4. Multiply the alcoholic ingredients' ABVs by their respective amounts, and then add those products together to calculate the combined ABV. In this example, multiplying 1 ounce of vodka by its ABV of 40 percent, or 0.4, results in 0.4, and multiplying 1 ounce of coffee liqueur by its ABV of 20 percent, or 0.2, results in 0.2. Adding 0.4 and 0.2 together results in a combined ABV.

5. Divide the combined ABV by the total volume of the drink. For this example, the total volume of the drink is 4 ounces, and dividing 0.6 by 4 results in 0.15, so the ABV for the mixed drink is 0.15 or 15 percent.