How Many Stamps Do I Need? The Guide USA – USPS

You’re looking to send mail. However, you don’t know how many stamps do you need to purchase? Postage can be a bit confusing because various options are available. United States Postal Service (USPS) provides a variety of choices, but we will discuss the best option for you.

We’ll explain the functions of each one of the US Postal delivery services, as well as the costs for them.

How Many Stamps Do I Need?

The two most frequently asked questions are, “how many stamps do I need to for a letter?” and “Under what conditions do you need more than one stamp?”

The answer is dependent on:

  • The size of the letter
  • The weight of the letter
  • Classification of the service (e.g. First class stamps, Registered Mail, and Certified).
  • The worth of the stamps

Domestic letter mail -Price Per Ounce

If you’re mailing a regular first-class letter to the U.S., Domestic Forever Stamps costs just 58 cents and provides delivery within 1 to 3 business days. The U.S. Postal Service last raised the cost for Domestic Forever Stamps from 55 cents to 58 cents by 2021. The cost for every additional ounce of your mail piece went up from 15 to 20 cents.

Forever Stamps are the postage stamps issued by USPS. They are non-denominational, meaning they will always stay at the current rate. But, it is vital to keep in mind that the price is only for the first one ounce. If the envelope weighs more than 1 ounce, you’ll need to pay more for each ounce.

Let’s examine the postage that you’ll have to pay for any letters that exceed one-ounce using Domestic Forever stamps under 3.5 ounces:

Domestic letter mail Price Per Ounce
A letter of 1 ounce1 Domestic Forever Stamp costs 58 cents.
 A letter of 2 ounces1 Domestic Forever Stamp and one additional ounce stamp at 20 cents costs 78 cents.  
A letter weighing 3 ounces1 Domestic Forever Stamp and two additional 20-cent stamps - costs 88 cents.
A letter weighing 3.5 ounces1 Domestic Forever Stamp, 1 Postcard Stamp, and one 10-cent stamp costs $1.08. 

Remember that once your envelope exceeds the 3.5-ounce limit, you have to look at rates for flats because there are big envelopes for mailing between 3.5 to 13 ounces. 

Domestic envelope requirements and cost

If you want to mail a letter using an envelope, you must comply with specific rules. It means that you have to measure the envelope before you purchase it.

The regulations are as follows:

Domestic EnvelopeRequirements & Cost
DimensionThe dimensions of an envelope are much more important than you realize. It should not be larger than 11.5 inches by 6.125 inches, not thicker than 1/4 inch, and it must be of uniform thickness.
ShapeThe envelope has to be rectangular. The square envelope must be at least 5 inches in size, are acclaimed as "non-machinable," and are prone to an additional 21 cent postage cost. The term "machinable" refers to a letter which can be processed through the USPS sorting system without issue.
Bendable*The envelope should be bendable. If not bendable, it'll be considered as "non-machinable," and you'll be charged an additional 21 cents.

Flat envelope costs and requirements

As previously mentioned, “flats” (or large envelopes) are required for shipments weighing 3.5 to 13 ounces. They must comply with the following standards:

Flat'sEligibility Criteria
DimensionThe dimensions of flat envelopes must be at atleast 6.125 inches by 11.5 inches and must not be more than 13 inches.
ThicknessFlat envelopes shouldn't be any thicker than 0.75 inches.
Bubble packets*Bubble packets are not permitted because it makes it thicker.

How many number of stamps for a large envelope (flats)? In the case of one ounce of the flat envelope, you can choose one Domestic Forever Stamp, 1×10-cents, and one postcard stamp, which will cost $1.08. You can also choose two domestic forever stamps and pay extra 8 cents. 

Domestic postcard rate and requirements

If you’re looking to send postcards within the United States, buying a postcard stamp for just 40 cents is less expensive than purchasing a Domestic Forever Stamp, which is 58 cents.

The postcard has to satisfy the following criteria to be eligible for this kind of stamp:

D.P.ShippingEligibility criteria
DimensionThe dimensions of the postcard must be at lease 3.5 inches high and five inches long. It shouldn't be any more than 4.25 inches height and six inches long.
ShapeThe postcard has to be rectangular.
ThicknessThe postcard should at least 0.007 inches thick, and not more than 0.016 inches thicker.

International shipping rates USPS

The most efficient way of sending letters from the U.S. to the U.K. is using Global Forever Stamps, which cost $1.30. If you choose to use Domestic Forever Stamps, make sure they’re at the minimum of $1.30. It is more expensive when your letter weighs more than an ounce because Global Forever Stamps only cover up to 2 ounces.

How many stamps do I need for a Letter?

Calculating the cost of postage for parcels can be a bit complex. When calculating the cost of parcel postage, it is necessary to know the weight, the size of the parcel, and the covering distance.

There are two methods to calculate how many stamps you’ll need:

  1. Calculating postage at the post office

Parcels are big for postbox. Therefore, you need to bring the package to the local post office. They will guide the price of the stamp there.

    2. Using a postage calculator

The United States Postal Service has created an online calculator which allows you to calculate the postage cost in advance. You must know the mail’s weight, size and class to use it. Once you have this information, enter it into an online calculator to calculate the postage price.

Where can I buy stamps

There are many ways to purchase stamps. You can purchase them online from:

Postage costs 2022

Letter's Price's
First-Class Mail letter (1 ounce) $0.58
First-Class Mail letter - each additional ounce $0.20
First-Class Mail flat/large envelope (1 ounce) $1.16
First-Class Mail flat/large envelope - each additional ounce $0.20
Postcard $0.40

Flat Rate Envelopes

Flat Rate Envelope's Prices
Priority Mail flat rate envelope $7.75
Priority Mail legal flat rate envelope $8.05
Priority Mail padded flat rate envelope $8.45
Priority Mail Express Flat Rate Envelope $23.50
Priority Mail Express Legal Flat Rate Envelope $23.75

International Mail & Packages

International Mail & Packages Price's
First Class Mail International letters (1 oz.)  $1.30
First Class Mail International Flats (1 oz.)  from $2.60


Canada Price's
First Class Package International Service - Canada (1 lb.) From $21.00
Priority Mail International (1 lb.) - CanadaFrom $37.47
Priority Mail International Flat Rate Envelopes $28.13
Priority Mail Express International Flat Rate Envelopes $44.95

What happens if I don’t have the right number of stamps?

If you don’t see a return address for the package and don’t use enough stamps in the first place, the post office may try to collect the postage fee from the recipient.

However, if they do not agree to pay for postage and do not have a return address, the package will be shipped to “dead letters.”

How to use USPS postage Calculator?

  1. Select the country you want to send the parcel to in the drop-down menu. You also have to select Zip code, date, and time. Make sure you select the right option from the boxes to confirm if you are sending live animals, hazardous material, and poultry.
  2. Choose which kind of shipping you want to use. Flat Rate Postcard, Flat Rate Envelopes, Flat Rate Boxes, or you can know the cost based on the shape and size.
  3. You will see the basic shipping cost. You can also select “display all options” at the top to see the cost of other shipments.
  4. You may decide to add additional options such as Certificate of Mailing, registered mail, and insurance.
  5. You will be able to see the final shipping cost after this. 
  6. If you don’t have additional items, you can calculate how many stamps you’ll need to cover the shipping label costs.

The Bottom Line:

If you plan to send a letter or postcard, ensure that you have mentioned the correct postal address and stamps. Then, you can put the letter in your postbox, in the blue collection box or drop it off at your local post office.

The process of using stamps can be frustrating. Use the above guide on the stamp to know the postage rate, or use USPS Postage Calculator to figure out the most affordable combination of stamps for a letter/package. This is our complete guide on ” how many stamps do I need”, if you have any questions, let us know in the comment section.

Where can I buy stamps?

Post Office: You can buy stamps from post office You can directly purchase from USA official website.
Mailboxes: Many people get stamps from here
Stamp dealers: You can buy old stamps from dealer
The Internet: Many online retails sell stamps like Walmart

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