What is the weight limit for first-class letters?

The weight limit for first-class letters being 13 ounces is correct because this threshold is established by the United States Postal Service (USPS). First-class mail is designed for lightweight items, and the 13-ounce limit enables the convenient and expedited delivery of personal and business correspondence. Items weighing up to and including 13 ounces can be sent using first-class postage and can also be tracked if desired. This makes it a reliable option for mailing various essential documents and small parcels.

The other weight options are either too low or exceed the established maximum for first-class letters. For instance, items above 13 ounces must typically be sent via other classes of mail, such as Priority Mail, which accommodates heavier parcels. Understanding these weight limits is crucial for ensuring that mail is processed correctly and efficiently through the postal system.