That depends on the capacity (size) of the glasses.
If each glass holds (10 and 2/3) ounces, then yes, 12 of them total 1 gallon,
but that's a very weird size for a glass.
Water tumblers (drinking glasses) are usually 8 or 12 ounces.
8-ounce glasses . . . . 16 of them make 1 gallon
12-ounce glasses . . . (10 and 2/3 of them) make 1 gallon
Buy a calculator. Actually your computer should have one under accessories. But any way, to answer your question: There are 128 ounces in a gallon. So 16 times 128 equals 2,048 ounces. 2,048 ounces divided by 12 equals 170.6666666666 or a little over 170 and a half glasses.
1536
9.5 bottles equal one Imperial gallon.
There are approximately 10.7 twelve-ounce glasses in a gallon.
12 w/8 ox left over
1 gallon equals 4 quarts, so 12 quarts is equal to 3 gallons.
12 quarts equal 3 gallons
8 cups 1 gallon = 16 cups 1 cup = 0.06 gallon
3 gal 1 gallon = 4 quarts 1 quart = 0.25 gallon
12
12 US gallons is approximately 1,536 ounces
12 qts 1 gallon = 4 quarts 1 quart = 0.25 gallon