Domestic first class letters up to 1 ounce cost 49 cents as of October 2015. Additional ounces for first class mail cost 22 cents per ounce. Discounted meter service postage costs 48 cents per ounce.
As of October 2015, first class flat packages up to 1 ounce cost 98 cents, and each additional ounce costs 22 cents. Postcards cost 35 cents in postage. Priority mail packages are based on a base amount for the size of the box, and prices start at $5.05 for the smallest size. Priority mail express also includes base prices, which start at $13.09 for the smallest package. International first class letter postage is $1.20 up to an ounce.