The inside dimensions of the most common 2-quart casserole dishes are square dishes that are 8 inches wide by 8 inches long by 2 inches deep or round dishes that are 9 inches in diameter and 2 inches deep. An inch or more is added for the outside dimensions, depending on the size of the rim and handles, if there are any.
For a recipe calling for a 2-quart casserole, other casserole shapes may be substituted by adjusting cooking time and temperature. An 11-inch by 7-inch by 1.5-inch baking pan and a 9-inch by 5-inch by 3-inch loaf pan are also capable of holding 2 quarts. The baking pan makes the filling shallower, so the baking time must be shortened and the temperature of the oven must be increased slightly. The filling is deeper in the loaf pan, so the baking time must be lengthened and the temperature must be lowered slightly.