You Just Wrote a Letter. Now What?
You’ve sealed the envelope, addressed it, and you’re ready to send it off. Whether it’s a birthday card, an important document, or a heartfelt note, the next question is universal: how much is this going to cost me? You head to the post office or your kitchen drawer for a stamp, and the uncertainty begins.
Is one Forever Stamp enough? What if it’s a little heavier? Does it cost more to send it across the country? The simple act of mailing a letter shouldn’t feel like a puzzle, but with changing rates and different service levels, it often does.
This guide breaks down the exact cost to send a letter in 2026, covering standard mail, priority options, and international postage. We’ll move past the guesswork and give you the clear, actionable numbers you need to get your mail out the door with confidence.
Understanding the Basics of Letter Postage
Before we get to the prices, it’s crucial to know what defines a “letter” for postal services. This isn’t just about size; it’s about weight, thickness, and flexibility. Getting this wrong is the most common reason letters are returned for additional postage.
A standard letter must meet these criteria:
- Maximum size: 11.5 inches long, 6.125 inches high, and 0.25 inches thick.
- Maximum weight: 1 ounce for the base rate.
- It must be rectangular and uniformly thick.
- It must be flexible enough to be processed by automated sorting machines.
If your mail piece exceeds any of these limits, it’s no longer a standard letter. It becomes a “large envelope” (flat) or a “package,” which costs significantly more to send. Always weigh and measure your envelope if you’re unsure.
The Workhorse: The Forever Stamp
The Forever Stamp is the cornerstone of personal and business mail in the United States. Its primary advantage is in its name: it always holds the value of the current First-Class Mail one-ounce rate, regardless of when you bought it or when you use it.
If you purchased Forever Stamps for 68 cents years ago, they are still valid to mail a one-ounce letter today, even though the rate has increased. This protects you from inflation and saves you a trip to the post office for new stamps every time rates change.
As of 2026, the price of a single Forever Stamp is 73 cents. This covers the postage for a standard one-ounce letter being sent anywhere within the United States, its territories, and to APO/FPO/DPO military addresses.
Current 2026 Mailing Costs for Letters
Here is the complete fee schedule from the United States Postal Service for First-Class Mail letters. These rates are effective and were last adjusted in early 2026.
Domestic Letter Rates (Within the U.S.)
For letters mailed to any location within the United States, including Puerto Rico, Guam, and other territories.
- 1st Ounce: 73 cents (One Forever Stamp)
- Each Additional Ounce: 24 cents
This means a two-ounce letter requires 97 cents in postage (73 + 24). A three-ounce letter requires $1.21 (73 + 24 + 24). You can use a combination of Forever Stamps and additional ounce stamps, or purchase a single stamp for the exact value.
Postcard Rates
While not a letter, postcards are a common related item. The current rate to mail a standard postcard domestically is 56 cents. Postcards have strict size requirements: they must be between 3.5 and 4.25 inches high and between 5 and 6 inches long.
International Letter Rates (Global First-Class)
Sending a letter outside the United States costs more due to the international agreements and handling involved. You cannot use a domestic Forever Stamp for this.
You need a Global Forever Stamp, which costs $1.65 as of 2026. This covers a 1-ounce letter to any country in the world. The pricing for heavier international letters is different and often requires a trip to the post office counter for precise calculation based on the destination.
When Your Letter Isn’t Standard
Many everyday mailings push beyond the standard letter boundaries. Here’s what that does to your cost.
Large Envelopes (Flats)
If your letter exceeds the maximum dimensions for a standard letter but is still flat and flexible, it’s classified as a “large envelope” or “flat.” This includes manila envelopes, large greeting cards, and legal documents in large envelopes.
The starting rate for a 1-ounce large envelope is $1.39. Each additional ounce costs 24 cents. The size and weight limits for flats are much larger, up to 15 inches long and 12 inches high.
Non-Machinable Surcharge
Some letters meet the weight and size standards but cannot be safely processed by machines. These require a non-machinable surcharge of 44 cents on top of the normal postage.
Common examples include:
- Letters that are too rigid (like a small plastic card).
- Envelopes that are square or nearly square.
- Items with clasps, strings, or buttons.
- Letters with an address parallel to the shorter side.
For a one-ounce, non-machinable letter, you would need $1.17 in postage (73 + 44).
Faster Delivery Options and Their Costs
First-Class Mail typically delivers within 2-5 business days. If you need guaranteed speed, you must upgrade your service, which comes with a higher price tag and tracking.
Priority Mail Express
This is the fastest service offered by the USPS, with next-day to 2-day delivery guaranteed, including weekends and holidays in many cases. It includes tracking and $100 of insurance.
The cost for a flat-rate envelope starts at $30.95. For a letter-sized envelope sent via Priority Mail Express, the price is typically calculated by weight and zone but generally starts above $28. This service is for urgent documents, contracts, or time-sensitive medications.
Priority Mail
Priority Mail offers 1-3 business day delivery with tracking and $100 insurance. It’s faster than First-Class but more affordable than Express.
You can use a Priority Mail Flat Rate envelope for a fixed cost of $9.90, regardless of weight (up to 70 lbs). For a simple letter sent via Priority Mail (not flat rate), prices start around $8.50 for a small weight, increasing with distance.
Practical Tips to Get Your Postage Right
Avoid returned mail and delays by following these best practices.
Weigh and Measure at Home
Invest in a small kitchen scale that measures in ounces. Weigh your complete, sealed envelope. Use a ruler to check its dimensions and thickness. Compare your results to the USPS standards mentioned earlier. This simple step prevents the vast majority of postage errors.
Use the USPS Online Calculator
The official USPS Postage Price Calculator is the most accurate tool. Enter your envelope’s details, weight, and destination (ZIP codes). It will give you the exact postage required and show you all available service options with their prices and delivery estimates.
Buy Postage Online
You can purchase and print exact postage from the USPS website or from authorized third-party services like Stamps.com. This is ideal for odd weights or international mail, as you print a precise label with a barcode. You can then drop the letter in a blue collection box or at the post office without waiting in line.
When in Doubt, Go to the Counter
If your letter is irregular, heavy, or going internationally, the safest option is to take it to your local Post Office. A clerk can weigh it, assess it, and apply the exact postage needed. You pay on the spot, and you have the assurance that it’s correct.
Common Troubleshooting and FAQs
Let’s address the frequent points of confusion.
What happens if I use insufficient postage?
Most likely, your letter will be returned to you with a notice asking for additional postage. Sometimes, the USPS may attempt to deliver it and collect the postage due from the recipient. To avoid embarrassment or delay, it’s always best to ensure correct postage upfront.
Can I use two Forever Stamps for a heavy letter?
Yes. Two Forever Stamps provide $1.46 in postage (73 + 73). This would cover a standard domestic letter weighing up to three ounces (which costs $1.21). You are effectively overpaying by 25 cents, but the letter will be delivered without issue. It’s a simple, if slightly wasteful, solution for a 2 or 3-ounce letter.
Do stamps expire?
No. Forever Stamps and all standard U.S. postage stamps never expire. They are always valid for the face value they represent. An unused stamp from decades ago is still valid mailing currency today.
How much is a book of stamps?
A standard book contains 20 Forever Stamps. At the 2026 rate of 73 cents each, a book costs $14.60. You can also buy rolls of 100 stamps, coils for businesses, and stamps with various designs.
Your Action Plan for Mailing Letters
Mailing a letter doesn’t need to be complicated. Follow this simple decision tree to ensure it’s done right every time.
First, prepare your letter. Seal it, address it clearly, and add a return address. Second, weigh and measure it. Is it a standard letter under 1 ounce? If yes, apply one 73-cent Forever Stamp. If it’s heavier, add 24 cents for each additional ounce.
If your letter is square, rigid, or has clasps, add the 44-cent non-machinable surcharge. If it’s larger than a standard envelope, use the large envelope rates starting at $1.39. For international destinations, use one $1.65 Global Forever Stamp for the first ounce.
For peace of mind, use the online calculator or visit the post office. Keep a supply of Forever Stamps and additional ounce stamps in your desk. This small preparation turns mailing from a chore into a simple, predictable task, ensuring your important messages and documents always reach their destination.
