Just had a friend ask me to make a house shaped cake. How do you guys calculate how many servings are in an oddly shaped cake?

Start with the number of servings each pan you use yields.

Try to keep track and estimate how much you carve away. It helps to fill a pan with the scraps to give you a better idea. So, if you're able to fill an 8-inch round pan with scraps, you've cut away approximately 10 servings.

Subtract a few servings from the final number to account for odd shaped pieces and general cutting difficulties.

That makes sense but, I'm trying to get an idea of how big to make it to get the no. of servings she wants (40-50).