How Many Stamps Do I Need?
Getting the right postage on my mail has been frustrating. But it wasn’t always this way, and I wish we could go back to an easier system.
I don’t mail things very often, but when I do I of course need stamps. And you might be thinking, Isn't this what Forever stamps are for? And it’s true that Forever stamps do make things easier. The United States Postal Service sells these stamps at the current price for a first-class letter, and they remain valid at the price for a first-class letter even when prices increase. This means that you can buy them in one year and not have to add extra small-value postage when the price goes up the next year; you can just use the same stamps and rest assured that you’re applying the proper postage.
So where’s the frustration? It comes when you want to mail something other than a simple letter.
Large Envelopes
The first problem is large envelopes. Officially, a “letter” has a maximum size of 6 1/8 in. by 11 1/2 in. (and a maximum thickness of 1/4 in.). Anything larger, like a 9 in. by 12 in. catalog or manila envelope, is called a “flat” and costs more to mail.
Here are the prices for letters and flats over the past ten years:
| Date | Price for Letter | Letter x 2 | Price for Flat |
|---|---|---|---|
| July 2025 | $0.78 | $1.56 | $1.63 |
| July 2024 | $0.73 | $1.46 | $1.50 |
| January 2024 | $0.68 | $1.36 | $1.39 |
| July 2023 | $0.66 | $1.32 | $1.35 |
| January 2023 | $0.63 | $1.26 | $1.26 |
| July 2022 | $0.60 | $1.20 | $1.20 |
| August 2021 | $0.58 | $1.16 | $1.16 |
| January 2021 | $0.55 | $1.10 | $1.00 |
| January 2020 | $0.55 | $1.10 | $1.00 |
| June 2019 | $0.55 | $1.10 | $1.00 |
| January 2018 | $0.50 | $1.00 | $1.00 |
| January 2017 | $0.49 | $0.98 | $0.98 |
| April 2016 | $0.47 | $0.94 | $0.94 |
| January 2016 | $0.49 | $0.98 | $0.98 |
(This table was compiled from historical price lists posted to USPS’s website, obtained through the Wayback Machine.)
Notice something? Before July 2023, the price for a flat was exactly double the price for a letter (except for a time it was actually slightly less), so you all you had to do for a flat was to put two Forever stamps. But since then it costs slightly more than double, so if you want to mail a flat you need additional postage. This means you have to either get small-value stamps, or add another Forever stamp which wastes money.
Heavy Items
The second problem is heavier items. The aforementioned prices for letters and flats are only for items weighing up to one ounce, and heavier items require a surcharge for each ounce of extra weight. Thankfully USPS issues “additional ounce” stamps, which like Forever stamps are valid at the cost of an additional ounce even when prices increase. (There are also dedicated two-ounce and three-ounce stamps, which function like a combination of Forever stamps and additional ounce stamps.)
The problem again has to do with flats:
| Date | Two-Ounce Letter | Two-Ounce Flat | Letter Add’l Ounce | Flat Add’l Ounce |
|---|---|---|---|---|
| July 2025 | $1.07 | $1.90 | $0.29 | $0.27 |
| July 2024 | $1.01 | $1.77 | $0.28 | $0.27 |
| January 2024 | $0.92 | $1.63 | $0.24 | $0.24 |
| July 2023 | $0.90 | $1.59 | $0.24 | $0.24 |
| January 2023 | $0.87 | $1.50 | $0.24 | $0.24 |
| July 2022 | $0.84 | $1.44 | $0.24 | $0.24 |
| August 2021 | $0.78 | $1.36 | $0.20 | $0.20 |
| January 2021 | $0.75 | $1.20 | $0.20 | $0.20 |
| January 2020 | $0.70 | $1.20 | $0.15 | $0.20 |
| June 2019 | $0.70 | $1.15 | $0.15 | $0.15 |
| January 2018 | $0.71 | $1.21 | $0.21 | $0.21 |
| January 2017 | $0.70 | $1.19 | $0.21 | $0.21 |
| April 2016 | $0.68 | $1.15 | $0.21 | $0.21 |
| January 2016 | $0.71 | $1.20 | $0.22 | $0.22 |
Since July 2024, the cost of an additional ounce is actually different depending on whether you’re mailing a letter or a flat. So now you can’t even trust an “additional ounce” stamp to provide the stated postage!
To be fair, the cost of an additional ounce for a flat is less than for a letter, and the stamp’s value is based on the former so you’d still be taken care of. But this discrepancy makes it harder to get exact postage.
Yes, I Mail Things That Are Both Large and Heavy
As you might imagine, these two problems can happen at the same time. The usual large and heavy items I mail are income tax returns (which I’ve written about before), and the required postage pretty much never lines up with the value of Forever and additional ounce stamps.
I wish USPS would go back to the old system, where flats cost twice as much as letters and the additional ounce charge is the same across both. But maybe that’s unrealistic at this point. One thing that might simplify this a bit is a new “Forever-style” stamp for flats. Or maybe they could set prices so that the difference between a letter and a flat is a multiple of the additional-ounce charge, who knows. The money being wasted in overpaid postage is not a lot in the grand scheme of things, so I guess the status quo is okay.
