When baking more than 1 frozen lasagna how much extra time do you add on?

When baking more than one frozen lasagna, generally, you don't need to significantly increase the baking time. Instead, you can add about 10-15 minutes to the total cooking time, but it's essential to check the internal temperature to ensure it's thoroughly heated. Additionally, make sure to space the lasagnas properly in the oven for even cooking. Always refer to the specific instructions on the packaging for the best results.