6 Inch Round Cake Pan Equivalent. 9 x 1 1/2 inches: Round = 3.14 x [6 x 6] = 113 square in.
If it comes out clean, the cake has finished baking. It forces you to make the recipe first so you can measure its batter; So a 20 cm (8 inch) round cake tin can be switched for an 18cm (7 inch) square tin and a 23cm (9 inch) round tin can be switched for a 20 cm (8 inch) square tin.
Round = 3.14 x [3 x 3] = 28 square in.
Length of square cake tin we now to need find the length (l) for the square cake. Round = 3.14 x [4.5 x 4.5] = 64 square in. For square cakes, use the round quantities below and deduct 1 inch from the round cake chart, or alternatively, see the cake tin sizes chart above. Round = 3.14 x [5 x 5] = 79 square in.