I had to research this today as a recipe I am going to add calls for a 2 quart casserole dish, I don’t have any Pyrex dishes that are ‘casserole’ dishes, I just have standard state of Kansas dishes, so I looked up the size of casserole dishes. I do use Pyrex dishes for nearly everything I bake.
Casserole Size and the Baking Pan Size in inches
1 1/2 quarts = 9x5x3 loaf pan
2 quarts = 8 inch square cake pan OR 7×11 cake pan
2 1/2 quarts = 9 inch square cake pan
3 quarts = 9×13 cake pan
4 quarts = 10×14 cake pan
Several good references are here: