What determines the postage for a single piece of First Class Mail?

The postage for a single piece of First Class Mail is primarily determined by the weight in ounces. In the United States Postal Service (USPS) system, First Class Mail pricing is structured to take into account the weight of the item being sent. Each ounce increment contributes to the total postage due. For example, mail weighing up to one ounce has a specific price, and the cost increases with each additional ounce.

While other factors, such as distance and type of service, may influence the overall cost of mailing or the delivery timeline, they do not directly set the postage for a standard First Class Mail piece. Packaging might affect the weight but does not independently determine postage pricing. Therefore, understanding that weight is the key factor in calculating First Class Mail postage is essential for accurate mailing practices.