I feel like it would be useful to know exactly how much alcohol is in a can or a bottle. Also why is alcohol the only thing measured in percentages and not sugar or caffeine or medicine?
ABV works for all types of packages. It could be helpful to know that a can of beer contains 18.6ml of alcohol, sure, but what about a bottle of whiskey or vodka? Is it better to know that it’s 40% alcohol or 300ml? Should a bar publish that a keg has 4.2 liters of alcohol in it?
With ABV you can compare alcohol across volumes.
X% of the cans volume tells you the exact amount. You can know with very simple math. The reason why is because historically, alcohol drinks are taxed based on the concentration, or percentage, of alcohol. Beer would be taxed at a lower rate than say whisky. It was all based on the percentage, or “proof”, of the beverage, not the actual amount. That way a small and large jug of whisky would be taxed at the same rate.
