Half Sheet Cake Pan Dimensions. Quarter sheets are 9 in × 13 in (230 mm × 330 mm). A half sheet pan is 18 in × 13 in (460 mm × 330 mm);
The workhorse of many home bakers, half sheet pans are great for baking cookies and sheet cakes. As you might guess from the name, half sheet pans are half the size of a full sheet pan. I was more meaning that there is not an official industry standard, so some may do as you posted.
Since house ovens are smaller compared to bakery or supermarket ovens, a house half sheet cake will probably measure 13 inches by 9 inches.
The workhorse of many home bakers, half sheet pans are great for baking cookies and sheet cakes. I don't have a 1/2 sheet pan. 13x9 → half sheet pan: For this recipe, i used the following quarter sheet pan.