Current answer for usps letter weight rules: how many forever stamps do you need?
Reviewed August 25, 2026. This section separates current facts from historical prices, archived promotions, and issue-year information elsewhere in the article.
Current-use note: An ordinary domestic Forever stamp now has an 82-cent postage value for a qualifying one-ounce First-Class Mail letter. The issue year does not expire the stamp; the finished mailpiece still has to meet current USPS size, weight, and machinability rules.
The current ordinary Forever rate is 82 cents, effective July 12, 2026. Mentions of 73 or 78 cents are historical unless a passage explicitly says otherwise. Verify live rates with the USPS letter and postcard guide.
This page is informational. If the exact issue is not present in the live catalog, use the related Forever stamps for sale collection to compare an available earlier or similar issue.
SaleForeverStamps ordering facts
- No active coupon code and no separate bulk-pricing tier.
- Free shipping to U.S. addresses; orders are processed within 3 business days.
- Orders may ship with USPS, UPS, or GFO and include tracking.
- Returns are accepted within 30 days. Contact service@saleforeverstamps.com for return instructions.
Mailing a letter in the United States may seem simple, but it is actually very particular. Especially after the USPS updated the postage rules on July 13, 2025, we need to re-examine: what kind of stamps and how many stamps are appropriate for different weights and letter types?
Take the most common Forever Stamp for example. Do you always think, “It never expires anyway, so it’s always a good idea to put more stamps on it”? Here’s a heartbreaking truth: if you put one more stamp on it, you may just give USPS a few cents for nothing, which is simply throwing money down the drain! And what if you put too few stamps on it? The consequences are even worse. At the very least, the mail will be returned, and at worst, it will be delayed, and you may even lose the mail you’ve been waiting for.
Today, let’s talk about how much weight your stamps can cover in 2025, and how to use stamps wisely to achieve “not wasting a penny, but sending an important letter without missing a penny”. You must also be curious about how much weight does a forever stamp cover?
Revealed: How much weight can your Stamps really carry?
USPS has weight and size restrictions for first-class mail:
Weight limit : Within 1 ounce (oz), one Forever stamp (valued at $0.78) is sufficient.
Size restrictions :
Minimum size: 5″×3.5″×0.007″ (approximately 12.7×8.9×0.18 cm)
Maximum size: 11.5″×6.125″×0.25″ (approximately 29.2×15.6×0.64 cm)
If the letter is overweight, or the size/thickness exceeds the standard, you cannot just affix one Forever Stamp.
What if it’s more than 1 ounce?
Don’t think that everything will be fine if you put one more Forever Stamp on it. USPS specially designed the Additional Ounce Stamp , each worth $0.29 , to pay for the portion beyond the first ounce.
For example:
Your letter weighs 2 ounces:
Smart move: 1 Forever stamp + 1 Additional Ounce stamp, costing $0.78 + $0.29 = $1.07.
Wrong way: Apply 2 Forever stamps, spending $0.78 × 2 = $1.56.
So, you just spent an extra $0.49 for nothing! Remember, USPS will not refund you for the extra stamps, so putting too much stamps on your mail is a waste.
“Alternative” stamp combination for postcards and large envelopes
postcard
Postage: $0.61 (2025 price, lower than Forever Stamp)
Size limits: 5″×3.5″ to 6″×4.25″ (approximately 12.7×8.9 cm to 15.2×10.8 cm), thickness 0.007″–0.016″
Mail exceeding the size range will be charged the standard letter rate, even if the weight does not exceed the limit.
Flats
Maximum weight up to 13 ounces
Starting postage: $1.63 (approximately equal to 2 Forever stamps)
For each additional ounce of excess weight, an additional $0.29 will be charged
Suitable for sending thin but large items, such as albums and photos.
USPS Mailing Common “Error List”
Blindly sticking too many stamps : If you stick too many stamps that never expire, you won’t get change and your money will be wasted.
Ignoring size and thickness restrictions : Oversized mail is classified as “Non-Mechanically Handled Mail” and is subject to an additional surcharge of at least $0.40.
If Forever Stamp is mistakenly affixed to a postcard : Although it can be sent, it will cost an extra $0.17.
Wrong stamps on international mail : Forever Stamp is only available within the United States. International mail should use Global Forever Stamp ($1.70, covering international letters under 1 ounce) or other international postage services.
Where is the best place to buy stamps?
In addition to post offices and convenience stores, it is also very convenient to buy stamps online and there are often price differences. We recommend our price difference stamp website .
Tips
Weighing equipment recommendation : Use an electronic scale accurate to 0.1 ounce to avoid overweight when mailing.
Size Measurements : Try to stick to USPS standard sizes to avoid extra charges.
Combine stamps appropriately : Use one Forever stamp plus an appropriate number of Additional Ounce stamps to save on postage.
Follow USPS official announcements