There are 82 cans of beer in a 7.75 gallon keg.
Assuming you are using 16oz pints, then there are about 62 glasses.
2 gal
2 cups
4 gal 1 gallon = 16 cups 1 cup = 0.06 Gallon
0.93 gal 1 gallon = 16 cups 1 cup = 0.06 Gallon
6 gal
6.25 gal
17272144 cups
There are 32 cups in 4 gallons.
5 gal 1 gallon = 16 cups 1 cup = 0.06 Gallon
0.78 gal 1 gallon = 16 cups 1 cup = 0.06 gallon
that is 48 cups
8 cups are about half a gallon.