The amount of postage required to mail six pieces of paper depends on various factors. The size of the envelope, the total weight, the destination address and the requested delivery speed all impact postage cost.
As of 2015, the cost to mail a 1-ounce standard stamped first-class envelope is 49 cents. A stamped standard envelope weighing between 2 and 3 ounces costs 70 cents to mail domestically. A stamped standard envelope weighing between 3 ounces and 3.5 ounces mails domestically for 91 cents. All envelopes weighing more than 3.5 ounces are charged the same rates as large envelopes regardless of their size.