Additional Ounce Stamps
2017-Uncle Sams Hat Stamp Additional Ounce Postage Stamps
Original price was: $29.00.$23.20Current price is: $23.20.
2023 School Bus Postage Stamps
Original price was: $29.00.$23.20Current price is: $23.20.Additional Ounce stamps pay the per-ounce charge beyond the first ounce on eligible First-Class Mail letters. The current value is 29 cents per stamp. Add one to a regular Forever stamp for an eligible letter weighing over 1 ounce through 2 ounces; add two for a letter over 2 through 3 ounces.
Choose the Right Additional Ounce Stamp
The products below are USPS-issued Additional Ounce postage, not ordinary one-ounce Forever stamps. Compare the package quantity and design shown on each product page. The printed denomination may be omitted because an unused Additional Ounce stamp keeps the current additional-ounce value for its service category.
| Eligible machinable letter | Current postage | Practical combination |
|---|---|---|
| Up to 1 ounce | $0.82 | 1 ordinary Forever stamp |
| Over 1 through 2 ounces | $1.11 | 1 Forever + 1 Additional Ounce stamp |
| Over 2 through 3 ounces | $1.40 | 1 Forever + 2 Additional Ounce stamps |
| Over 3 through 3.5 ounces | $1.69 | Pay the full amount; whole-stamp combinations may overpay |
Rates shown are effective July 12, 2026. A square, rigid, lumpy, oversized, international, or service-enhanced mailpiece can use a different price calculation even when its weight is within these ranges.
Additional Ounce Is a Service Category
“Forever” can describe more than the ordinary one-ounce letter stamp. An Additional Ounce Forever stamp remains tied to the future Additional Ounce rate, but it does not become an ordinary Forever stamp. Its current 29-cent value must be combined with enough other postage to meet the full mailing price.
What About Penguin Stamps?
The 2015 Penguins stamp is an Additional Ounce stamp, even though shoppers sometimes search for “penguin Forever stamps.” USPS issued the emperor-penguin design in panes of 20 and coils of 100. It pays the current Additional Ounce amount, not the current one-ounce Forever amount. This category explains that service distinction; availability is limited to the products displayed below.
Before You Add Postage
- Weigh and measure the finished, sealed mailpiece.
- Confirm that it qualifies as a machinable domestic letter.
- Start with the one-ounce letter price, then add 29 cents for each additional ounce or fraction.
- Use the USPS calculator when the envelope is square, rigid, thick, oversized, international, or includes an extra service.
Read when Forever stamps need extra postage for the full decision guide, or use the USPS postage calculator for a specific mailpiece.
Sources: USPS Notice 123; USPS Penguins stamp announcement. Rates checked September 1, 2026.