Additional Ounce Stamp Value: 29 Cents in 2026

An additional ounce stamp is worth 29 cents, the price the US Postal Service charges for each ounce a stamped letter weighs over the first. That price has applied since July 13, 2025 and was left unchanged in the July 12, 2026 price change (USPS; Wikipedia's table of US postage rates).

The stamps carry no number. The Postal Store lists the current School Bus design as a "non-denominated Additional Ounce Rate" stamp, and Wikipedia notes that since 2015 additional-ounce stamps have been marked with their use rather than a printed price. So an additional ounce stamp bought years ago for 20 or 24 cents pays today's 29 cents, in the same way that an old Forever stamp pays today's 82-cent letter price.

A stamp that does show a number, such as 21c, is a denominated stamp and is worth exactly that amount as postage.

Stamped letter prices from USPS Notice 123, effective July 12, 2026, with the stamps that add up to each price exactly:

• Up to 1 oz: 82 cents, one Forever stamp
• Up to 2 oz: $1.11, one Forever stamp plus one additional ounce stamp
• Up to 3 oz: $1.40, one Forever stamp plus two additional ounce stamps
• Up to 3.5 oz: $1.69, one Forever stamp plus three additional ounce stamps

Because the extra-ounce price is the same at every step, the combination is always exact and you never overpay.

Three things change the price:

• Over 3.5 ounces a letter is priced as a large envelope (flat). Flats start at $1.69 for 1 ounce, cost $2.56 at 4 ounces and rise 29 to 31 cents an ounce to $5.24 at 13 ounces (Notice 123).
• Square, oversized or unusual envelopes pay the 49-cent nonmachinable surcharge; the USPS lists them from $1.31.
• Rigid, nonrectangular or unevenly thick large envelopes pay parcel prices, according to the notes to Notice 123. That can catch thick items such as trading cards in a hard holder sent in a large envelope.

Yes, as long as the total covers the price. Stamps.com, which sells printed postage, states the rule plainly: the postage on the envelope must match or exceed the current rate, and stamps can be combined to get there.

For a 1-ounce letter at 82 cents:

• Three additional ounce stamps make 87 cents, which covers it and overpays by 5 cents.
• Two make 58 cents, which is 24 cents short.

The cheapest way to use up a drawer of additional ounce stamps is on the letters they were made for: one Forever stamp plus one, two or three of them on heavier letters, where they count at full value with nothing wasted.

The extra-ounce price has not always gone up. From Wikipedia's table of US postage rates, for letters:

• January 22, 2012: 20 cents
• January 26, 2014: 21 cents
• May 31, 2015: 22 cents
• April 10, 2016: 21 cents, part of a rare general price cut
• January 27, 2019: 15 cents, cut when the first-ounce price rose to 55 cents
• January 24, 2021: 20 cents
• July 10, 2022: 24 cents
• July 14, 2024: 28 cents
• July 13, 2025: 29 cents
• July 12, 2026: 29 cents, unchanged (USPS)

In 2017 the price was 21 cents, which answers a common question about stamps bought that year: a non-denominated additional ounce stamp from 2017 cost 21 cents and now pays 29.

The Postal Store also sells single stamps for heavier letters. In September 2026 it listed:

• Two-ounce stamps at $1.11 each ($22.20 for 20): Elie Wiesel, Wedding Blooms and Katharine Graham designs
• Three-ounce stamps at $1.40 each ($28.00 for 20): Sarah Orne Jewett and Saul Bellow designs
• Additional ounce stamps at 29 cents: School Bus, $5.80 for 20 or $29.00 for 100

The postage is identical either way: a two-ounce stamp costs the same as a Forever stamp plus one additional ounce stamp. The single stamp saves space on a small envelope; the additional ounce stamps are more flexible, because the same stamps cover 2, 3 and 3.5 ounces.

We found no market that pays more than postage for ordinary modern additional ounce stamps; they are printed in large numbers and sold at every post office. Treat them as postage, which they are at full value. The exceptions are the same as for any modern stamp: a genuine printing error, such as missing colour or missing die cuts, can be collectible, and our guide to stamp errors and varieties explains what to look for.

Research and drafting were assisted by AI, and every price and date was checked against the sources listed below: USPS Notice 123 and the USPS price announcement of April 9, 2026, the USPS Postal Store, Stamps.com and Wikipedia. The stamp combinations and the over- and under-payment figures are our own arithmetic from those prices. Prices are those in effect on September 25, 2026.