The number of Forever stamps you need depends on the weight and type of your mail:
- For a standard 1-ounce first-class letter within the U.S., you need one Forever stamp , which currently costs 73 cents but will increase to 78 cents on July 13, 2025, if approved
- If your letter weighs more than 1 ounce, you need one Forever stamp plus additional postage for each extra ounce. For example, for a 2-ounce letter, you would need one Forever stamp plus one additional ounce stamp (currently 28 cents, rising to 29 cents)
- For international mail, one Global Forever stamp covers a 1-ounce letter. Alternatively, you can use three domestic Forever stamps to cover international postage for a 1-ounce letter
. For postcards sent internationally, the cost is about $1.50, so you might need two Forever stamps plus some additional postage to meet that amount
- For larger or irregularly shaped envelopes, or heavier mail, you will need more postage accordingly
In summary, to mail a typical 1-ounce letter domestically, one Forever stamp is sufficient. For heavier or international mail, you will need additional stamps or Global Forever stamps based on weight and destination
