cost to mail a letter overnight

cost to mail a letter overnight through USPS is available with Priority Mail Express, which offers guaranteed overnight delivery. The cost of mailing a letter overnight depends on its weight and size, with the starting price being around $26.35 for small envelopes weighing up to 0.5 pounds. The price increases with larger or heavier envelopes. USPS also offers a flat-rate envelope option for Priority Mail Express, which allows you to ship a standard envelope up to a certain weight for a fixed price.