How much postage for 4 oz envelope?

The postage required for a 4 oz envelope depends on the mailing service and destination. For domestic First-Class Mail in the U.S., the cost is typically around $1.20 for a 4 oz envelope as of 2023. However, rates may vary, so it's best to check the latest rates on the USPS website or at your local post office for the most accurate information.