You would need 416 fluid ounces total, which would be 13 quarts.
16 ounces per mug times 26 gives you the total amount of fluid ounces that you need (416). Once you do that all you have to do is convert 416 ounces to quarts. If there are 32 ounces in one quart, you would take 416/32 to get your answer/total number of quarts needed which is 13 quarts.
Hope this helps you tons :D
