Originally Posted by swimintheundertow

I said it backwards anyway. 120 precent would be 240 proof.

I guess it's mathematically possible to be more than 100% this is how wiki says you find alcohol by volume.

Given a value in ABW (alcohol by weight) you can convert it easily to ABV using the following formula:

ABV = 1.25 × ABW
or, inversely:

ABW = 0.8 × ABV

I was just looking around and I saw up to 300 proof.