what is the maximum weight of first-class mail® parcel?
Lets answer your question in several parts; The Short Version First: 1: First Class Letter - Max weight is 3.5 oz. 2: First Class Large Envelopes - Max weight is 13 oz. 3: First Class Parcels - Max weight is 13 oz. Long Version: You asked about âFirst Class Mailâ and the weight limits. Mail is defined as âLetters and packages conveyed by the postal systemâ. See Google.