USPSHow many stamps do I need for a letter?

Postage for a 6” x 9” envelope is determined by the postal classification rate used for shipping.

First Class is the most popular service when mailing to an address in the US.Priority Mail Flat Rate can be cheaper if the envelope is over 3.5 ounces in weight or 14 inch in thickness.Several extra services are included in the flat rate fee of Priority Mail Express Service.

One $.50 first class rate stamp is required for a 6” x 9” envelope weighing up to 1 ounce.You have to pay $0.21 for each additional ounce.It will cost you $0.71 for weight between 1 and 2 ounces.The cost of weight between 2 and 3 ounces will be 92 cents.

The larger envelope rates will be charged if the envelope is more than 3.5 ounces in weight.

If the contents of the envelope have an important business or correspondence value to either the sender or receiver, there are additional postal services available for added fees.

A domestic flat rate of $6.70 for a 6” x 9” envelope is offered by the USPS.Proof of mailing, protection in the postal system, and confirmation of delivery are some of the additional services offered by the Priority Mail Flat Rate system.