0.02957

1 fluid ounce in US is equivalent to 0.02957 litter. This is based on the earlier definition of one gallon equaling 231 cubic inches. This measurement at first glance does not seem to have any tie to mass, however it is believed to have come from a previous measure of a gallon as being 224 cubic inches (just 7 cubic inches less, both numbers being multiples of 7) which was used because it was the exact volume of 8 pounds of wine.