The perfect pie box size is 1” larger than the dessert. For example, the ideal dessert container for a 5” pie is a 6” box. Using a smaller box size may damage the dessert while in transit.
Also, when you search for the perfect paper pie box, keep in mind that the container should be wide enough to fit the pie plate securely. If you are not sure about the plate size, all you need to do is to grab a ruler and measure the plate’s diameter.