What Does Additional Ounce Mean On Stamps?
What Does Additional Ounce Mean On Stamps? A letter weighing 1 ounce will need one first-class stamp. As of January 2019 a first-class stamp costs $0.55, every additional ounce is charged at $0.15. What is an additional ounce? Each additional ounce of a single-piece letter will increase in cost from 15 cents to 20 cents,