Usually the Post Office provides the best deals, but if you have a shipment that has to be there overnight, UPS’s Simple Rate Next Day Air Saver service can’t be beat on cost. Opting for flat-rate packaging, offered by all three carriers, can mean huge savings.The Post Office was cheapest across the board for 1- to 3-day shipping, with prices 40-55% less than UPS and 43-63% less than FedEx.

UPS is consistently the less expensive of the two, although FedEx flat-rate options do offer some deals. FedEx and UPS provide far more options for time-sensitive shipping, with guaranteed delivery as early as 8 a.m.To find the cheapest shipping rates, we compared the cost of sending hypothetical 5- and 10-pound packages coast to coast, from New York City to a residential address in Los Angeles. Pricing generally varies based on the size and weight of the package and the origin and destination, although all three carriers provide flat-rate boxes that ship for a fixed price regardless of weight. All offer standard ground delivery, various two- or three-day delivery options, and guaranteed overnight shipping. Postal Service, United Parcel Service (UPS), and FedEx remain the biggest names when it comes to consumer shipping.

Medium vs large flat rate box