Cristina, it is somewhat complicated. For most cakes, you will need to have more structure in the batter in order to increase pan size, becaus the batter has to “hold iitself up” over the distance between pan sides. For butter cakes, this means reducing baking powder as pan size goes up- this what the Rose factor chart in the Cake Bible helps you do. For other cakes, like chiffon, it is very difficult to change pan size without drastically altering the texture of the cake. For Genoise, I have had success just multiplying the recipe to get the right amount of batter to fill the pans 2/3 full for a larger cake. I can’t recommend the Cake Bible highly enough, it will help you learn all of this.