How Many Stamps Do I Need for a Large Envelope?

Learn about paying for the proper amount of postage to cover the weight of your large envelope with the US Postal Service
how many stamps do I need for a large envelope
Written on:

If you’re sending a large envelope in the mail, you’ll need to make sure you’ve purchased the proper amount of postage for it. Postage covers the weight of letters, with one Forever stamp accounting for the first ounce of an envelope’s weight. If your large envelope weighs more than one ounce, you’ll need more than one postage stamp in order for USPS to accept it.

The Amount of Stamps You Need for a Large Envelope Depends on How Many Ounces the Envelope Weighs

Like most rules in the shipping and mailing industry, the amount of stamps you need for a large envelope depends on how many ounces your envelope weighs with all the contents inside of it. Most large envelopes containing documents that USPS delivers weigh one ounce or less. Therefore, most manila and large envelopes only require one Forever stamp to send them.

That said, there are often cases where a large envelope weighs more than just one ounce. A letter covered by First-Class stamps can be up to three ounces, and if your letter weighs more than one ounce, you’ll need to pay for the “Additional Ounce” postage to cover each additional ounce up to three ounces total. These stamps don’t cost the full 58 cents, but only 20 cents per each additional ounce. If you’d like to see some examples of “Additional Ounce” postage, you can check out these stamps on the USPS website. You can also pick up Additional Postage stamps for 5 or 10 cents each, but in our experience, if you need to pay for an extra ounce, it makes the most sense to just spring for the Additional Ounce postage stamps.

Pro Tip: If your large envelope weighs three ounces, you can technically use three Forever stamps to cover the full cost of postage, too! You’ll be paying a little more than you have to, but USPS will accept the letter, no questions asked.

Make Sure Your Envelope isn’t a Poly Mailer

Here’s something important to remember when loading up your envelope with stamps: make sure you’re in fact sending an envelope and not a poly mailer! USPS considers large envelopes (like manila envelopes) as “Flats,” and you can only purchase First-Class postage to send Flats in the mail. Poly mailers, on the other hand, are more three-dimensional envelopes that USPS requires you to use a shipping service for, such as First Class Package or Priority Mail.

The best way to determine if USPS will classify your envelope as a “Flat” is to double-check its measurements. For USPS to consider a large envelope a Flat for mailing, your envelope’s dimensions must be:

  • A minimum of 5” x 3.5”
  • A maximum of 11.5” x 6.125”
  • No thicker than 1/4″

If your envelope fits within those parameters, then you’ll need to mail it and not ship it!

Sending Envelopes is Different from Sending Postcards

Another thing to keep in mind is that the postage for a manila envelope is much more expensive (percentage-wise) than the cost of postage to send a postcard. Postcard stamps are only $0.40 each, while the cost of a regular Forever First-Class stamp is $0.58.

You can technically use a Forever Stamp to send a postcard, since $0.58 more than covers the fee…although you’ll be overpaying by $0.18. If that matters to you, then you can order postcard stamps directly off the USPS website, or you can get some at your local Post Office.

On the other hand, if 18 cents won’t move the needle all that much, you can keep a roll of Forever stamps handy and use them for all of your mailing needs…whether you’re sending letters, large manila envelopes, or postcards.

Last Updated:
Share on Facebook Share on Twitter Share on Reddit Share via Email


Post a Comment
  1. PJ

    This page is completely useless – only the comments made by people wanting to help others who have landed here are of use.

  2. Tom Slick

    I’m confused about the rate. If the first oz is $0.58 and each additional oz is $0.20 then a 3oz envelope should be $0.98. Right? Yet you say it takes 3 Forever stamps when two should do $1.16 or have I missed something. Pete says that the 1st oz is two Forever stamps or which he somehow calculates at $1.26 or $0.62 each Forever stamp? I need to mail a large envelope with 2.7 oz which Peter says is $1.74 so I am not sure what to do.

    • Barbara E Campbell

      Did you factor in the thickness of the envelope, if it is not under 1/4″ thick you will pay a surcharge. If the envelope exceeds 12″ in size it incurs an over size charge too.

  3. wsher

    A maximum of 11.5” x 6.125”
    differs from everywhere else on the web,
    says 12 x 15 x 3/4

  4. Ken

    Totally waste of time here. Why can’t you just give us some idea how much do we need like let’s say 10 page of 8.5×11 paper!

  5. Cole

    I thought this would be a guide that would show postage rates for mailing a manila envelope…not a poly mailer…not a postcard. I’m pretty sure that anyone over the age of 3 knows that a postcard is not the same as an envelope. But thanks for making that clear to us. I still have no idea how many stamps to put on my manila envelope with a document that totaled 7 sheets of paper inside

  6. Shirley G

    Why can’t you tell us how much it costs to mail a 4 oz flat or any other flat for that matter. I could have just about driven the envelope to where it is going. The USPS does not need to be funded. We could get screwed by private companies just as well.

    • Heather

      I’m trying to find out if I can mail a manilla envelope that measures 6.75 x 9.75 and 11.5 from corner to corner that weighs 1.8 Oz. Any help would be appreciated.

      • Pete

        My full paper sheet size manila envelope with 2 sheets of paper inside weighed just under 1 oz. Here are rates from post office
        Large Envelopes (Flats)2
        Weight Not Over (oz.)
        1oz $1.26 (i.e. 2 forever stamps)
        2 1.50
        3 1.74
        4 1.98
        5 2.22
        6 2.46
        7 2.70
        8 2.94
        9 3.18
        10 3.42

  7. D T

    You didn’t answer the question dumbasses!

    • Cara

      Oh my, they most certainly did answer the question. I’m sorry but you shouldn’t call names like that especially when you aren’t educated on the topic. Please tell me how they didn’t answer the question? Do you expect them to magically know the weight of your envelope? Lol

  8. Nancy

    Correct wordage is the NUMBER of stamps, not the AMOUNT of stamps. And I still don’t know how much it should cost to mail an oversized envelope!

    • Cara

      Right, because you need to have it weighed!!! A website can’t tell you your weight. I knew that going in, as I would hope you did, however this site let me know that my mail is greater than three ounces. Therefore, it saved me from throwing on a bunch of stamps and sending my important mail.

    • Cara

      How do you expect a website to tell you the weight of your “oversized” envelope???? Come on people. Use your brains! If it’s under 3 ounces put 3 stamps on it, if not, you have to take it to your post office bc it has to be mailed through them!!!!

      • Vicky

        I have a 5by 11 envelope with two scratch offs ” two forever stamps ?

  9. Jack

    This is bs. Shame on you for wasting our time.

    • Cara

      Oh my, not a good look for you. They did answer your question. They certainly saved me from mailing out my envelope bc. based off what they said, mine weighs over 3 ounces. What, you don’t mean to tell me you thought this site was physic and could magically determine the weight of your envelope? HAHAHAHAHAHA

    • Cara

      Jack, what’s wrong? What aren’t you able to understand?

      • Isaac

        What I needed to know I definitely found my answers. From the reading but more from the comments lol. People people we are all here for if not the same, then a close reason. We shouldn’t be fighting calling names we looking for help and people ar trying their best to inform us so that we shan’t have these questions ever again. The vulgar language used for commenting hate on the ones going out of their way to help is quite unnecessary. Keep your cool you came to the site as an adult why not leave like one. I have much respect for all of us regardless we are all the people lets not fuckin forget that shit when we or others can’t comprehend shit. Goddammit yall, acting like a bunch of bitch ass pussies wherever yall can find an opening for that shit. Shut the fuck up go jek off and come back in 20 minutes damn. Motherfuckers srbtryin to learn some important shit and these bitches are straight trollin on any fuckin comment board they come to. Take that hate and aim that at the real enemy. I don’t know if yall ate aware but this shit right here.. this is how we start looking like a bunch of cowards and taking the backbone from our country. Fuckin shut the shit down and appreciate. Goddamn what the fuck yall. Thanks for the advice btw lol

  10. Sandra

    This DOES NOT tell me the postage needed for an oversized envelope although the title of the page indicates it will. GEEZ Waste my time.

    • Cara

      How do you figure??? You do realize the only way to know the correct postage is by having the envelope weighed. With that, how would you expect a website to tell you the weight of your envelope?? I think it did exactly what the title said.

  11. Robert

    Typical useless government gibberish-if not a monopoly bankrupt!!!

    • Alex

      This is not a government website but I’m not surprised that you don’t understand that as you also don’t seem to understand what a monopoly is either.

  12. Rhonda

    How many stamps do I put on a regular white envelope for 10 pictures regular size pictures 4×6

  13. Frank Lindsey

    totally useless load of cut-n-paste copied crap


Post a Comment

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.

Related Shipping Guides