Convert ingredient proportions from the original recipe to fit your own baking pan. Add ingredients and provide dimensions to check how much you need.
Your pan is 1.27x larger
Yes, scaling by area works well for focaccia, cinnamon rolls, or sheet pan pizzas where the dough spreads across the bottom. For loaf pans, volume calculations are sometimes more precise, but area multipliers provide a very close estimate.
For home baking, it is usually fine to round to the nearest gram for dry ingredients. For very small quantities like baking powder, baking soda, or yeast, try to be as precise as possible, using a digital scale.