How do I know what size to order?

With SmartAC.com SmartFilters you don’t need to know the size when you order. We will gather the exact size from you during the onboarding process. Once we have the size we will ship your filters. All you need to know at checkout is whether you have a standard 1” thickness filter or the much larger 4, 5, or 6” whole home media filter that fits inside your air handler/furnace