What is Postage for 8.25 X 5.75 envelope?

The postage for an 8.25 x 5.75 envelope typically falls under the category of a "large envelope" or "flat" in the U.S. Postal Service. As of my last update, the postage for a standard large envelope starts at around $1.16 for the first ounce. However, rates can vary based on weight, destination, and service type, so it's best to check the USPS website or visit your local post office for the most accurate and current rates.