One Forever stamp covers a standard letter#
How much does it cost to mail a letter? For a standard letter inside the United States, $0.82 with a stamp, the July 12, 2026 First-Class Mail rate for a 1 oz letter. A Forever stamp is always worth the current 1 oz letter rate, so a stamp you bought years ago still covers today's letter.
"Standard" is doing real work in that sentence. USPS prices a letter at the base rate only when it is:
- 1 oz or less. A few sheets of paper in a regular envelope usually stay under an ounce, but a kitchen scale settles it.
- Letter-sized. A standard #10 business envelope or a greeting-card envelope qualifies. Anything larger than 6 1/8 inches by 11 1/2 inches by 1/4 inch thick is priced as a large envelope.
- Flexible and rectangular. Square cards, rigid contents, clasps, and lumpy items trigger a surcharge.
If your letter misses any of those, the price goes up. The rest of this page tells you by how much, so you can put the right postage on it the first time.
What your letter costs: common mailpieces, priced#
Each row below is a letter someone actually mails, with the stamped retail price that applies in 2026. Prices are for delivery within the fifty states and Washington, D.C.
What common letters cost to mail in 2026
Mailpiece | Why USPS prices it this way | Stamped price |
|---|---|---|
One or two pages in a #10 envelope | Standard letter, 1 oz | $0.82 |
Greeting card in a rectangular envelope | Standard letter, 1 oz | $0.82 |
Square greeting card | Nonmachinable shape, 1 oz | $1.31 |
Multi-page letter that weighs 1 to 2 oz | Letter, second ounce | $1.11 |
Thicker letter that weighs 2 to 3 oz | Letter, third ounce | $1.40 |
Heaviest letter allowed, 3.5 oz | Letter at its weight ceiling | $1.69 |
Unfolded pages in a 9 x 12 envelope, 1 oz | Large envelope (flat) | $1.69 |
Same envelope at 2 oz | Large envelope, second ounce | $1.98 |
Standard postcard | Postcard rate | $0.65 |
1 oz letter sent Certified Mail | Postage plus the Certified Mail fee | $6.37 |
Source: Stamped retail prices effective July 12, 2026. Source: USPS Notice 123.
Two patterns explain most of the table. Weight adds $0.29 per ounce to a letter. Shape and size move a piece into a different category: a square card pays the nonmachinable surcharge, and a 9 x 12 envelope pays large-envelope prices even at 1 oz.
How many stamps do you need?#
A Forever stamp is worth $0.82, whatever you paid for it. Match the postage due to whole stamps, and expect to overpay slightly on heavier pieces unless you buy additional-ounce stamps.
Forever stamps needed by weight and format
Weight and format | Postage due | Forever stamps needed |
|---|---|---|
Letter up to 1 oz | $0.82 | 1 |
Letter up to 2 oz | $1.11 | 2 |
Letter up to 3 oz | $1.40 | 2 |
Letter up to 3.5 oz | $1.69 | 3 |
Large envelope up to 1 oz | $1.69 | 3 |
Large envelope up to 2 oz | $1.98 | 3 |
Large envelope up to 3 oz | $2.27 | 3 |
Source: Stamp counts assume Forever stamps only. Two stamps cover $1.64; three cover $2.46.
Two Forever stamps on a 2 oz letter overpay by $0.53. If you mail heavier letters often, buy additional-ounce stamps, which are sold at the $0.29 additional-ounce price, and pair one with a Forever stamp instead of doubling up. The Post Office counter and the USPS postage price calculator will give you an exact figure when the piece is unusual.
What makes a letter cost more than one stamp#
Weight. Letters are priced by the ounce up to a 3.5 oz ceiling. Above that, USPS treats the piece as a large envelope or a package. A few sheets in a regular envelope are typically under an ounce, but glossy inserts, thick card stock, or a dozen pages are not. Weigh it.
Size. A letter must fit within 6 1/8 inches by 11 1/2 inches and be no more than 1/4 inch thick. Exceed any dimension and you are mailing a large envelope, which starts at $1.69 rather than $0.82. Folding pages to fit a #10 envelope is the cheapest fix.
Shape and rigidity. USPS adds a $0.49 nonmachinable surcharge when a letter cannot run through sorting equipment. The common triggers: a square or unusually proportioned envelope, contents that make it rigid, clasps, strings, buttons, loose items inside, or a polybag. Wedding invitations and photo cards land here often.
Destination. Every price on this page is domestic. Letters to other countries use the Global Forever stamp and international rates; check the USPS international mail page before you seal the envelope.
Stamps, metered postage, or sending it online#
A stamp is the simplest way to pay, and slightly the most expensive. Metered postage, printed by a postage meter or postage software, prices the same 1 oz letter at $0.78. Postage providers and online services use the metered rate, then add their own charges.
Sending the letter online changes what you are paying for. With Postmarkr you upload a PDF, enter the address, and the letter is printed, folded, stuffed, and mailed as First-Class Mail for a per-letter price starting at $2.05, with color at $2.52. That price includes the paper, envelope, postage, USPS address verification, and a status trail in your dashboard. It costs more than a stamp because it replaces the printer, the envelope, and the trip. Whether that is worth it depends on how many letters you send and what your time is worth; the mail cost calculator does the math for your volume.
For a one-off birthday card, buy a stamp. For twenty tenant notices due Friday, send them online. The guide to the four ways to send a letter compares the trade-offs in more depth.
Certified Mail and other extras#
Certified Mail is the most common add-on for letters that matter. It is a $5.55 fee on top of postage, which puts a 1 oz stamped certified letter at $6.37. Return Receipt, the delivery record with a signature that comes back to you, adds $2.91 electronically or $4.65 for the green card. The Certified Mail cost guide walks through every combination.
Priority Mail, Priority Mail Express, insurance, and signature confirmation are priced separately from First-Class letters. Use them when speed or coverage matters more than the extra dollars; a plain letter does not need them.
Check these five things before you mail#
- Weigh it. Anything beyond a few sheets, or anything with an insert, goes on the scale.
- Measure it. Confirm the envelope is within letter dimensions, or budget for large-envelope pricing.
- Flex it. If the envelope does not bend, or the shape is square, add the nonmachinable surcharge.
- Place the postage top right. Return address top left, delivery address centered. The envelope addressing guide covers the line-by-line format that keeps a letter from bouncing.
- Know the current rate. USPS adjusts prices periodically; the USPS rates page tracks the current First-Class figures, and the First-Class Mail rates guide explains each format's price in full.
Get those right and a standard letter costs exactly one stamp. Get one wrong and it comes back to you, postage due, a week later.