We have 4 different sized ovens and need to cook 150 pounds of Idaho® potatoes for a fundraiser. Is there a formula we can use to determine the appropriate cooking time for all these potatoes?

Not sure of a formula but here is what I would do: Using one oven thermometer, turn all the ovens to 400°F and measure the inside temps of each oven to get the most consistent reading as possible between all of them. Adjust the oven temps to get a matching temperature between all 4 ovens. Next wash, prick the skin with a fork (to allow the steam to escape) and prepare to bake the potatoes. Don’t wrap them in foil. Try to use similar pans for all of the potatoes. ONLY place the potatoes one level deep on the pans for more even cooking or bake them right on the rack. The potatoes are done when the internal temperature of the largest potato reaches 210°F. This will take approximately one hour, unless the potatoes are huge, which may then require the cooking time to be lengthened by about 10 minutes. To transport the potatoes to the function, you can wrap them in foil or you can pre-heat a cooler with hot water, drain the water and add in the potatoes.