Most avid drinkers know that both ABV and proof refer to the alcohol content of a spirit, but what is the difference between ...

For example: 80-proof vodka (40% alcohol; the most common type) has 64 calories per 1oz 86-proof vodka (43% alcohol) has 70 calories/1 oz 90-proof vodka (45% alcohol) has 73 calories/1 oz 100 ...