First Class Postage Rates 2024 By Weight

First Class Postage Rates 2024 By Weight. First class mail is the cheapest way to ship a package weighing less than 16 oz with dimensions less than 22″ x 18″ x 15″ in. A first class letter can only weigh up to 3.5 ounces per mail piece.

Click here to know about article contents, weight or size limits. If you want to mail letters, postcards, and flats, first class mail.