Generally - whole bottles of hard booze (in this country) are sold as fifths. So a fifth is an entire bottle.

If a quart is 32 oz and a fifth is 25.6 oz then a fifth is 0.8 quarts. A quart ia 0.946 liters - so 0.8 X .946 = .757 liters.

That about 3/4 of a liter to you - you british dog.

Kathleen