What Is the USPS 1st Class Rate for a Letter Weighing 0.8 Ounces?

A letter sent first class rate via USPS weighing 0.8 ounces can cost between .48 and .70 cents depending on the shape of the envelope or whether it’s stamped or metered.

Letters sent in a envelope that meet the following dimensions are the cheapest: Height of 3-1/2 inches to 6-1/8 inches, length of 5 inches to 11-1/2 inches and a thickness of .007 inches to 1/4 of an inch. Letters sent in an envelope with a square shape, an odd-shape, or if they have a rigid object sticking out of an otherwise standard envelope are more expensive. Metered letters cost the sender one cent less than stamped letters.