Hi @stevevaeshotmail-com
Normally the measurements of the trays that the chef uses are the measurements that I mentioned previously.
It also depends a lot on the size of the oven. But basically that is the size of 35×45 centimeters. Remember that the sizes of trays are infinite, it depends a lot on the brand of utensil or brand of oven. But you can start with the measurement we mentioned above. If your oven cavity is smaller, you can prepare half the recipe and use a tray measuring approximately 18×22 centimeters.
We hope this information is useful.
Greetings.