There are no such things as one gallon pecks, but one US liquid peck equals 2 US gallons or 256 fluid ounces
128 liquid ounces per gallon of any liquid
0.42 gallon equals 53.76 fluid ounces.
128 oz in a gallon
1 US gallon = 128 fluid ounces
1/2 gallon is 64 fluid ounces.
I assume you mean liquid ounces. Unfortunately there are different definitions of gallons and liquid ounces - which is just one of many reasons to prefer the metric system. In the U.S., one gallon = 128 liquid ounces, so you divide the number of liquid ounces by 128.
1 gallon [US, liquid] = 128 ounces [US, liquid] 2 gallon [US, liquid] = 256 ounces [US, liquid]Fluid ounces divided by 128 = gallons
128 fluid ounces per US gallon.
1 US gallon is 128 fluid ounces. 1 Imperial gallon is just under 154 fluid ounces. (153.72)
128 oz
1 US gallon is 128 ounces