This is a very good article from Epicurious.com Any Size Pan Will Work for Your Cake With This Cheat Sheet | Epicurious

There’s more to accurately sizing up or down than doubling or halving a cake recipe. Refer to this cheat sheet and you can bake brownies or cake with any size pan.
— Read on www.epicurious.com/expert-advice/cake-pan-conversion-chart-article