An 8" round cake pan that is 2" high hold 6 cups of batter. A 5x2" cake pan hold 2+ 2/3 cups batter. So your 4.5 probably hold about 2 cups. So with a recipe that calls for an 8" cake pan you'd be able to make 3 of your 4.5 cake pans. On the baking time - check your cakes at the half point time of a regular size cake.