How Many Stamps per Ounce/How Many Ounces for One Stamp? Solved

Communication with another person today usually involves an electronic device of some sort. Emails, text messages, Facebook, Twitter, Snapchat — we’ve all succumbed to the ease of using our computers or phones for communication. Gone are the days of sitting down and writing a good old-fashioned letter to tell someone we’ve been thinking of them or sending someone a postcard from our vacation spot. But, what do you do if Grandma doesn’t have any computer device and you want to send her a birthday card or if you have a bill you can’t pay online and have to send through the mail? This article will help you determine how many stamps per ounce you need.

How Much Is a Stamp?

If you want to mail a letter today, one stamp will cost you $0.49. If you want to mail a postcard, the stamp will be slightly cheaper — only $0.34.

If you’re the type to always need a stamp, it may be best to stock up on stamps now before the cost continues to rise. In 2007, the United States Postal Service unveiled the Forever stamp, a non-denominated stamp that can be used, as its name implies, forever. Even when the cost of a stamp fluctuates, a forever stamp can still be used to mail a letter that weighs one ounce or less within the U.S. with no additional postage necessary.

As an example, in 2013, it cost $0.46 to mail a letter weighing one ounce or less within the United States. Because the stamps printed and issued in 2013 did not have the value of $0.46 printed on them but instead states “Forever,” a book of those stamps can still be used today even though the cost of a stamp has increased to $0.49.

Suggested Article: Where to Buy Stamps: 50+ Places (Gas Stations, etc)

Letters That Need More Than One Stamp

A letter weighing an ounce or less and mailed within the U.S. needs one Forever stamp. Each additional ounce costs $0.21, so your two ounce letter needs approximately a stamp and a half. Don’t cut your stamp in half (it won’t be good anymore) — for letters over one ounce, save yourself money by just using one Forever stamp and then paying the post office directly for the remaining postage.

Letters weighing over 3.5 ounces are considered large envelopes. Large envelopes weighing more than 13 ounces are considered parcels, rather than letters, and will be charged according to USPS’s schedule for parcel prices. If you know how much your envelope weights, you can use the U.S. Postal Service’s postage rate calculator to determine how much you’ll have to pay.

Where to Put Stamps on the Envelope

You should place your stamp in the right-hand hand corner of the envelope you wish to mail, on the address side. If more than one stamp is needed, the stamps should not overlap. Though the United States Postal Service website doesn’t state if there is a maximum number of stamps that can be placed on an envelope, it does have a guideline that stamps should not cover the addresses. Go to this USPS page for more information on stamp placement.

Want to make it easy? Here’s where to buy pre-stamped envelopes.

Sending Mail Internationally

It costs $1.15 to send a letter or postcard that weighs one ounce or less internationally. This includes Canada and Mexico. If your letter weighs more than one ounce, the cost of the postage will vary by country. See a full chart of USPS international postage fees.

Other Classifications of Mail Service

The costs quoted above are for First Class Mail as defined by the United States Postal Service. There are other services available that will get your letter to its destination faster, but these will be more expensive. You can sometimes save money by choosing slower mailing methods for certain types of mail.

1. Media Mail

2. Priority Mail Express

3. Priority Mail

  • Timing: 1 to 3 business days, which is the same delivery time-frame for First Class Mail.
    • The difference is that the post office offers flat-rate packaging up to 70lbs for Priority Mail so this could be cheaper than sending First Class. This service also includes a tracking number and insurance.
  • Fees: Start at $6.65
  • More information available on the USPS website

4. USPS Retail Ground

In Summary

USPS sells stamps for your letters and can help you determine the best and most cost-efficient method of sending your letter or package. If you simply need stamps to mail a letter, you can also turn to a number of other stores, including online stores. So, while you may not be mailing letters every day, when you do need to send one, now you won’t be left wondering where to buy a stamp to stick on it.


    • Lindsey Desmet says:
      First Quarter Finance logostaff

      Hello, Karen! Unfortunately, we are unable to provide specific postage estimates. You may want to sign up at JustAnswer, where an expert can provide a thorough answer to your question. (Note that FQF may receive a commission if you sign up at JustAnswer and ask a question.)

  • I have a little box that ways less than 13 ounces. Let’s say it ways 13 ounces, how many forever stamps will I need to put on the box?

    • Kathleen Wilson says:
      First Quarter Finance logostaff

      Hi Jeremy,
      If my calculations are correct, it looks like you’ll need about 7 stamps. Instead of putting stamps on individually, you can go to the post office and just have them weigh your box and then put one stamp on it that covers the full cost. You can also check out the USPS Postage Price Calculator
      for a better idea of how much it will cost — you can put in your zip code, the zip code of where you’re sending the item, the weight, and shape, and get an exact price quote.

  • I’m a little bit confused, in the third paragraph you state that if a package weighs 1oz or less, you can use a forever stamp, but every ounce over that is $.21.., so you go in to say that it would be wasting a forever stamp to put two on there, but what’s the alternative when all you do have is forever stamps?

    • Rebecca Turley says:
      First Quarter Finance logostaff

      Hi Jenna,

      Often times, you can save money by going into the post office and asking them to weigh your package/envelope for you. That way you can pay the exact amount of what it will cost to mail your package instead of wasting money by putting two forever stamps on it when it may be only slightly more than 1 ounce.