How Many Stamps do I Need

How to know how many stamps to use. . . . it can be a bit of problem as using stamps to send a letter or package can be tricky, but you have to be free from frustration as the number of stamps needed is dependent on the size, weight, and class of the item to be mailed.

If you have above information ready with you, punch them into an online postage price calculator provided by the US Postal Service to calculate the cost of postage stamps instantaneously.

How to Know How Many Stamps to Use : METHODS

  1. Using a Postage Calculator
  2. Calculating Postage at the Post Office

Method 1: Using a Postage Calculator

Step 1

  • It is best to use a Forever stamp for all standard mail items. A single Forever stamp is enough to mail a package placed in a commercial envelope with measurements 11.5 inches by 5 inches (29 cm by 13 cm) with weight 28 g or less. A larger package, exceeding the above criteria, will need extra postage, which can be calculated using an online postage calculator.
  • As of January 2020, the price for a single Forever stamp is between $0.50 to $0.55.
  • Forever stamps are beneficial to mail letters, greeting cards, and paper items with weight less than 28 g.
  • To post a standard commercial envelope outside the United States, it is necessary to paste a Global Forever stamp. Global Forever stamps cost around $1.15 per piece.

Step 2

  • Measure envelopes or packets which seems more massive than the standard size, using a ruler or measuring tape to measure the exact details of length and width of the envelope or parcel. If the packages and envelopes are bulkier and tend to have a thickness, in that case, do include the thickness also with length and width. The overall size of the package will be considered to calculate the fair price of postage.
  • Take correct measurements to remain on the safe side. It would be best if you always rounded the figure, up or down, depending on the instructions of the postage calculator.
  • Stamps are for small-sized packages. For the bigger ones, you are suggested to go to the nearest post office rather than doing it on your own.

Step 3

  • Weigh the package whenever you include gifts, photos, or some extras things. It will be required to use a scale which is sensitive to register the weight of packet in ounces or grams. To weigh envelopes and small parcels, ordinary kitchen scales will be great. For heavier ones, use a digital bathroom scale.
  • Generally, every postage calculators, while calculating the price of postage, will round up the weight of the item.
  • In case, there is no access to a scale; then it is better to take the package to the nearest post office to weigh and post it with all dues.

Step 4

  • It is better to specify the class of the mailing item.
  • There are three standard mail categories/classes in USPS.
    • Ground
    • Priority
    • First Class
  • Both the weight of package and delivery speed required must be considered while sending a mail.
  • Ground mail
    • generally referred to as “standard shipping.”
    • typically takes 2-8 business days for arrival
    • best for mailing large quantities of mail at once
    • best handling oversized mail packets
    • saves money when there is no urgency for arrivals
  • Priority mail
    • typically delivered within 1-3 days
    • makes sending large items more affordable
    • flat rate envelope or box option available
    • costs fixed regardless of weight up to 70 pounds or 32 kg
  • First Class mail
    • usually delivered in 1-3 days
    • weight is limited to 13 ounces or 370 g
    • Heavier packages require additional postage.

Step 5

  • Give the information of the package to a postage price calculator as required. With the size, weight, and class of the package, enter the destination with postal code, sender’s postal code, along with time and date of shipment. After the submission of info, the mailing cost will be shown to figure out how many stamps are needed.
  • It is necessary to give accurate package information to make it easier and possible to pay the correct postage.

Step 6

  • Postage price is divided by the price of a Forever stamp. The rounded number after division is the number of forever stamps you will exactly need. Let’s say, the postage cost comes to $2.32, then divide 2.32 by 0.50 to get 4.64 and after rounding up for a total, you will have to use 5 forever stamps.
  • Never forget to round up. It ensures enough postage as fractions in the postage must be accounted for.
  • Alternatively, buy special stamps in smaller values, like 1 cent, 2 cents, 3 cents, 5 cents, and 10 cents to make up the difference of extra postage.

Step 7

  • Apply the stamps by peeling the sticky backing off the stamps and sticking onto the package. Position stamps in the upper right hand corner to make it more easily visible to the mail handler.
  • Arrange multiple stamps in 1 or 2 rows, without overlapping.
  • Take postage stamps to the post office for assistance if you are having any difficulty in pasting them onto the package.

Step 8

  • It is recommended to take large overstuffed packages weighing more than 13 ounces or 370 g, those who can not be put into the residential mailbox, to the post office for shipping for direct processing.
  • Postal clerks will calculate the price of postage and sell the required number of stamps to you.
  • In some preferred areas, the postal service permits to print out a shipping label and schedule a pick up from home, in case you do not want/ have time to visit the nearest post office.

Method 2 : Calculating Postage at the Post Office

Step 1

  • Bring the sealed package to the post office
  • Secure the flap holding the envelope or package closed.
  • Package must be neatly addressed, no over writings and free from extra information like old shipping labels.
  • Check stuff, seal, and address of the packet before arriving at the post office to save time.
  • You can purchase mail accessories like envelopes, mailers, and stamps at the post office if anything is absent/missing.

Step 2

  • Get the packet weighed.
  • You may tell the employee on duty to weigh of the package to calculate the correct postage.
  • The assigned staff will place and weigh to provide you with the exact cost on the spot.
  • The mail clerk may also request your postal code, the destination of the parcel, and type of the mail opted.
  • As told earlier, Priority mail arrives faster, but First Class mail is less expensive.
  • Keep in mind; First Class mail is available when package weighs 13 ounces or 370 g or less.

Step 3

  • Paste the number of stamps as required to the item.
  • After affixing the stamps, hand your parcel over to the postal clerk.
  • Since you are already at the post office, the clerk will print out and stick the mailing label on the package after checking the shipping cost.
  • It will be cheaper to use your stamps
  • No need to pay for postage separately.
  • Otherwise, no need to bother, the postal employee on duty is there to help.


If you don’t know how much your item weighs, you can always take it to your local post office and have them take care of the weighing and calculation for you. With the above points to consider, it is clear by now, how to know how many stamps to use.