How much is a 1.5 liter of Smirnoff vodka?

1.75 liter of vodka is a 1/2 gallon and a 1/2 gallon is 59 1/8 ounces.

A standard pour or shot is 1.5 ounces.

Therefore, you get 39 drinks out of a 1.75 liter with about a half ounce left.