How Much Does an Envelope Weigh?

How much does an envelope weigh? If you ask this question, it won’t be possible to answer it in a single word. The reason is that envelopes come in different designs, so their shape and weight also differ.  

However, the #10 envelope, the most common envelope, measuring 4.5 inches x 9.75 inches, weighs an average of 0.238 oz or 6.75 grams. 

Whatever shape of envelopes you choose, their average weight will be between 0.1 to 0.5 oz. This article will explore the weight of different sizes of envelopes.

Let’s get started!

Weight of Different Envelopes

Envelopes were measured using an in-house scale, thus may not accurately represent all paperweights.

  • #10 envelope: The classic business envelope, measuring 4.5 inches x 9.75 inches, weighs an average of 0.238 oz.
  • #9 envelope: Typically put inside #10 business mail reply envelopes. The envelope measures 3.875 inches x 8.875 inches and weighs 0.229 oz.
  • #8 envelope: Larger business-sized envelopes in which a check fits. The envelope measures 3.625 inches × 8. 625 inches and weighs 0.222 oz.
  • 6 x 9 standard-size envelope: Ideal for letters, postcards, and holiday cards. The envelope measures 6 x 9 inches and weighs 0.247 oz.
  • 9×12 envelopes: These envelopes are appropriate for shipping letters, photos, large postcards, papers, etc. They are the perfect option for sending over long distances and weigh about 28#.

Find all size of USPS envelopes and postcard size here: Standard Letter & Postcard Sizes

The above description shows that the 6 x 9-inch envelope is heavier than the others. These envelopes are designed with fancy paper stock for shipping holiday mailers. Therefore, the 6 x 9-inch envelope is heavier than the normal commercial envelope. 

The weight of the envelopes naturally increases when you place items inside them. So, each time you send a letter, you must measure the envelope precisely to determine the cost of mailing. 

If you ask how many pieces of paper can fit in an envelope with one stamp, it depends on how much weight is in your letter or envelope. With one Forever stamp, you can send a letter weighing up to 1 oz. 

Also Read: Where Can I Buy Stamps Besides The Post Office?

How Can You Calculate Your Mail Cost?

How Can You Calculate Your Mail Cost?

A piece of paper usually weighs 0.1696 ounces. So add 0.238 to 0.1696. The result will be 0.40 oz – the weight of a one-page letter. This weight is much less than that required for a standard First-Class letter, which would require only a single stamp.

As a general rule, the maximum authorized for a single stamp is always one letter with five sheets of paper. So your postage for one ounce of mail will be $0.63.

You should use two stamps on any letter that has more than five pages in the envelope. The weight limit for First Class is 3.5 ounces, which is a lot for any standard envelope.

Also Read: How Much Is A Book Of Stamps in 2023?

USPS Mail Size and Weight Rules

USPS mail size and weight rules

Everything that the US Postal Service transports are typically weighed in ounces. The weight can add up quickly if you’re mailing a big envelope or an envelope that’s thick and composed of heavy material. 

The maximum envelope dimension allowed for First-Class mailing is 5.125″ x 11.5″ x.25″. Consider all of these while mailing to adhere to USPS requirements. However, a normal envelope can typically hold up to five pieces of paper with just one stamp. 

To find out how much postage will be required to ship your specific letter or package, you need to know the USPS’s current pricing.

Also Read: Cheapest Place To Buy stamps – Save Money on Stamps

Types of Paper You Can Use For Your Standard Envelope Weight

The market offers various types of paper suitable for different purposes and budgets when it comes to making envelopes. You can select the appropriate paper type based on your mailing requirements. Below are some examples of commonly used paper types for envelope production.

Surfaced Enhanced White Wove

If you’re looking for a paper to create regular-weight envelopes or letters, Surfaces Enhanced White Wove paper is an excellent choice. This type of paper is available in standard 20# to 20# paper weights and produces envelopes that are suitable for mailing items.


Wove is the most cost-effective method for designing standard letter weight and size envelopes. Because of its short fibers and smooth finish, it is a common material for making envelopes. Woven envelopes come in a variety of colors and weights.


If you need to use heavy-weight envelopes, consider using brown Kraft paper. It has a sturdy construction with long fibers, making it an excellent option for sending compliance and transactional documents. Envelopes made with Kraft paper are designed specifically for this purpose.


Specialty envelopes come in a variety of weights, sizes, and colors. For direct mail marketing, they are the ideal choice.


To promote sustainability in your mailing practices, Recycled envelopes are a great option if you send a large volume of letters. These envelopes are available in various sizes and weight options.


For the shipping of crucial mail items, tear-resistant envelopes with a heavy-weight construction are readily available. Additionally, waterproof covers with water-resistant properties provide added protection and assurance that your documents will remain undamaged during transit.

Also Read:

USPS First Class Mail Features

  • This is an economic mailing class for shipping lightweight letters or packages.
  • Forever Stamps can be used to send First-Class mail pieces which are never invalid. The letter weighing 1 ounce is covered with one Forever stamp.
  • The delivery times for USPS First-Class mail are 1 to 5 business days for letters and 2 to 5 business days for packages.
  • The weight and dimensions of a standard envelope for your letter determine the First-Class mail price.
  • The USPS imposes a non-machinable surcharge on unusually shaped pieces of mail, such as lumpy, square, and rigid envelopes. 

FAQs on USPS Envelope Weigh

How many pages weigh 1 ounce?

Each page of paper weighs 0.1696 ounces. So, you can mail 5 pages and a slandered size envelope with 1 ounce First class stamp.

What lb is standard copy paper?

20lb is standard copy paper weight. Most printers and copy machines use 20lb copy paper.

How much does an 8.5 x11 envelope weigh?

A 500 sheet ream of 20 lb letter paper (8.5″ x 11″) weighs nominally 5 lbs.

How much can an envelope weigh with one stamp?

An envelope can weigh up to 1 ounce (including papers) to mail with one First class forever stamp.

How much does a paper and envelope weigh?

A standard envelope weighs 0.238 oz and a 8.5 x11 size paper weighs 0.1696 ounces.


Since envelopes are made from different types of paper, they vary in weight. Whichever type of envelope you choose, be sure that your mail items will fit snugly inside the envelope. This article will clear all your doubts regarding the weight of the envelope.

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