How Many Stamps Do I need?

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Working out exactly how many stamps you need to send a parcel or letter can be a confusing process.

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Skip to find out how many stamps you need to send:


To work out exactly how many stamps you need you will need to know:

  • The size of your letter or parcel.
  • The weight in grams or ounces.
  • What class you need to send it.
  • The address you are sending your parcel or letter to.
posting a letter

How Many Stamps Do I Need To Send A Letter In The U.S?

New Rate*Total CostStamps Required
Postcard$0.381 x Postcard stamp
1 oz. First Class Letter$0.551 x 1 oz. Forever stamp
2 oz. First Class Letter$0.701 x 2 oz. Forever stamp
3 oz. First Class Letter$0.851 x 3 oz. Forever stamp
1 oz. First Class Large Letter**$1.001 x 3 oz. Forever stamp
& 1 x Additional Ounce stamp
2 oz. First Class Large Letter**$1.151 x 3 oz. Forever stamp
& 2 x Additional Ounce stamp
3 oz. First Class Large Letter**$1.301 x 3 oz. Forever stamp
& 3 x Additional Ounce stamp
First Class Letters additional ounces charge$0.15Additional Ounce Stamp

A letter weighing 1 ounce will need one first-class stamp. As of January 2019 a first-class stamp costs $0.55, every additional ounce is charged at $0.15. So if you are sending a 2-ounce letter you will need $0.70 worth of postage stamps.

Be aware that prices may vary depending on where you buy your stamps from.

*Rate effective from January 27, 2019 – last checked 30th April 2020.

**A large letter is any envelope that exceeds 6.125 inches (15.5cm) high, 11.5 inches (29.2cm) wide or exceeds 0.25 inches (0.63cm) thick. The maximum size for large letter pricing is 12 inches (30.48cm) high, 15 inches (38.1cm) long and 0.75 inches (1.9cm) thick.

How Many Stamps Do I Need To Send A Parcel In The U.S?

Calculating the number of stamps required for a parcel is a bit more complicated than it is for letters. This is because parcel postage is charged by weight and size of the parcel as well as the distance it is travelling.

Parcels are usually too big to deposit in a mailbox so you will have to take it to the post office to get in despatched in which case it is easiest to ask them to sort the postage for you. However if you want to know how much you will be expected to pay, or you want to print your own postage label, then you can use the United States Postal Service postage calculator.

To use the United States Postal Service postage calculator follow these steps:

  1. Enter the destination country in the drop-down box, and the Zip codes you are sending the parcel from and to along with the date and time you will be sending it. Also select the correct option in the boxes to confirm if you are sending any live animals, day-old poultry or hazardous materials.
  2. Select which type of shipment you wish to use; Flat Rate Postcard, Flat Rate Envelopes, Flat Rate Boxes or you can find the price based on shape and size.
  3. You will now be given the price for your requested shipping options  – select “display all options” at the top to compare costs for other shipping options.
  4. You can then choose to add extra options including Certificate of Mailing, Insurance, Registered Mail etc.
  5. The next step will show you your final shipping cost.
  6. If you haven’t selected any extras then you can just calculate how many stamps you will need to cover the shipping cost. If you have added extra options you will need to get a shipping label printed either at a post office or you can print one yourself via the USPS Click & Ship page.

How Many Stamps Do I Need For UK Deliveries?

royal mail postbox

If you live in the U.K and are mailing to a U.K address then postage rates are worked out by a flat rate based on weight.

The table below shows how many stamps you will need based on the weight of your letter.

Mail Type & WeightNumber Of Stamps – 1st classNumber Of Stamps – 2nd class
Letter*  – 100g or less11
Large Letter** 100g or less22
Large Letter** 101g – 250g23
Large Letter** 251g – 500g33
Large Letter** 501g – 750g44
Parcel*** 751g – 1000g55
Parcel*** 1001g – 1250g87
Parcel*** 1251g – 1500g1012
Parcel*** 1501g – 1750g1113
Parcel*** 1751g – 2000g1417
Parcel*** 2001g – 4000g1821

* Letter may incur extra charges if they exceed dimensions of 24cm x 16.5cm x 0.5cm.

** Large letters may incur extra charges if they exceed dimensions 35.3cm x 25

*** Parcels may incur extra charges if they exceed dimensions of 45cm x 35cm x 16cm.