To be specific… http://www.benjerry.com/flavors/vanilla-ice-cream
2000 calories / 250 calories per serving = 8 servings.
8 servings * 1/2 a cup = 4 cups.
4 cups / 2 cups in a pints = 2 pints, or half a gallon.
If you ate a gallon tub of ben & jerries ice cream, you would get 4000 calories. Twice what you want.