figuring out a serving size

I found this yummy banana french toast casserole type thing on delish.com, I figure it will work great when we have family brunch, or maybe even for xmas morning. The site gives the recipie and also the nutirtional info, but it deosn't say how much is a serving or how many the dish serves. Is there any mathmatical way to figure that out? I figure I can enter all the ingrediants into the calculator thing on sparksrecipies.com but that may take a while. Any easier way?

Here is the recipie if anyone is interested. At 570 calories and 20 grams of fat is it much higher than my usual breakfast, but I figure a brunch is a rare treat and it's kind of combining two meals.

6 tablespoon(s) butter or margarine
1 1/2 cup(s) packed brown sugar
5 large ripe bananas, cut diagonally into 1/2-inch-thick slices
1 (12-ounce) long loaf French or Italian bread, cut crosswise into 1-inch-thick slices
6 large eggs
2 cup(s) milk
2 teaspoon(s) vanilla extract
1 teaspoon(s) ground cinnamon
1/2 cup(s) sliced almonds or coarsely chopped walnuts or pecans

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Directions

1. In microwave-safe small bowl, heat butter in microwave oven on High 1 minute or until melted. Stir sugar into butter until moistened. With fingertips, press sugar mixture onto bottom of 13-inch by 9-inch glass baking dish. (It's okay if mixture does not cover bottom.) Spread fresh or dried fruit over sugar mixture; top with bread slices, cut sides down.
2. In medium bowl, with whisk, beat eggs; whisk in milk, vanilla, and cinnamon. Slowly pour milk mixture over bread; press bread down to absorb egg mixture. Sprinkle with nuts. Cover with plastic wrap and refrigerate at least 2 hours or overnight.
3. Preheat oven to 350 degrees F. Remove plastic wrap from baking dish. Bake, uncovered, 45 to 50 minutes or until bread is golden brown and knife inserted in center comes out clean. Let stand 10 minutes before serving.


Note: If you don't have bananas, substitute 3 to 4 very ripe pears or peaches (about 1 1/2 pounds), sliced; or 1 cup dried cherries, cranberries, or raisins.

Nutritional Information
(per serving)

Calories 570
Total Fat 20g
Saturated Fat 11g
Cholesterol 191mg
Sodium 465mg
Total Carbohydrate 89g
Dietary Fiber 5g
Sugars --
Protein 13g
Calcium --