Pan geometry, worked from area
Scaling batter without scaling the pan is how a cake ends up raw in the middle. What matters is area, not the number on the label. An eight inch square pan is 64 square inches. A nine inch round pan is 63.6. Those two are interchangeable, and almost nobody realises it because the labels look nothing alike.
Every pan figure in the guide is computed from its stated dimensions with the formula shown, so you can check the arithmetic and apply it to a pan that is not listed. For tall pans, where area alone misleads, there is a measure-it-with-water procedure instead of a borrowed number.