If you’re wondering…what proof is vodka? I’m sure you’ll find the overly common answer…80 proof. Although that’s somewhat correct, it’s not entirely true. Yes, a vast majority of vodka in the U.S. is 80 proof. In fact, U.S. regulations require vodka to be at least 80 proof. However, the spirit can be 100 or even 120 proof. Here I’ll explain the alcohol proofing system and alcohol by volume (ABV).