What size mailing boxes does usps have

The United States Postal Service (USPS) offers a variety of mailing box sizes to fit different package dimensions and weights. Here are some common USPS mailing box sizes:

Small Flat Rate Boxes

Medium Flat Rate Boxes

Large Flat Rate Boxes

Regional Rate Boxes

Priority Mail Boxes

Specialty Boxes

Please note that these sizes are subject to change, and it's always best to check with the USPS website or a local post office for the most up-to-date information on mailing box sizes and weight limits.