Sending a letter or package through the mail is one of the easiest things you can do.

Ideally, you need to put three things on your envelope or packaging – **a destination address, return address, and a stamp**.

While placing a destination and return address on an envelope is straightforward, many people get confused about the number of stamps they need when sending a letter.

The number of stamps on an envelope or package will depend on many factors, including delivery timeframe, size, weight, and destination.

Furthermore, there are many different types of postage stamps, and all of them differ based on the type of shipping, cosmetic factors like design, and postage value.

But assuming you are sending a standard letter domestically, you will only need one stamp on the envelope. And if your parcel or letter weighs three ounces or more, you will need one stamp plus two additional ounce stamps.

## How to know the number of stamps to use

If you are sending out mail, either domestically or internationally, it is helpful to know the number of stamps you will have to add to your envelope or parcel.

The bulkier the letter, the more stamps you will need and the more expensive it will be to send your parcel. Here is a guide on what you should do.

### 1. How many stamps do I need for a letter?

If you are sending a standard letter domestically, **you will only need one stamp on your envelope**. This is either the Forever Stamp or First Class Letter stamp. It should be placed at the top-right corner of the parcel or envelope.

You will only require one stamp to send a standard letter internationally. However, in this case, you require the Global Forever Stamp.

A standard letter measures 11.5 inches (29 cm) by 5 inches (13 cm) and weighs 1 ounce (28 g) or less. If your parcel is larger than these measurements, you will need extra postage.

The USPS Forever One Ounce Postage Stamp price is $0.58. Any additional Once Forever Stamp will cost you an extra $0.20. The Global Forever Stamp costs $1.30.

### 2. How many stamps do I need per ounce?

If your letter weighs one ounce or less, you need one stamp to send it domestically or internationally. That should cost you about $0.58.

Typically, a four-page letter weighs around one ounce. But if the parcel weighs two ounces, you will require one Forever Stamp plus one additional ounce stamp.

So, assuming your letter weighs two ounces, you will have to pay $0.78 to get the two Ounce Forever Stamp.

A three-ounce parcel requires one Forever Stamp and two additional ounce stamps at the cost of $0.98. For every additional ounce stamp, you will have to pay an extra fee of $0.20.

If your letter is five pages long or weighs more than once ounce, and you have a thicker envelope, here is what you should do:

- Use your kitchen scale to measure the weight of the envelope
- Use a postage calculator to determine your mailing cost
- Divide the postage cost by the price of one stamp

After the division, you get the number of stamps you will need to place on your envelope.

### 3. How many stamps do I need for a large envelope?

When it comes to large envelopes or packages, you need to measure them to determine the number of stamps to buy. First, use a ruler to determine the length and width of the envelope.

Also, you will have to include the thickness of the parcel and the length and width. Once you get the overall size, it will help you to figure out the postage cost.

The first ounce you get for the large envelope means you need one stamp, costing $0.58. For each extra ounce, you will need one additional ounce stamp.

So, if the envelope weighs three ounces, you will need two domestic, one domestic Forever, and one additional ounce stamp.

### 4. How many stamps do I need for a postcard?

A postage stamp is necessary when sending a postcard domestically. The postcard should not be larger than 6 inches by 4.25 inches (standard size).

An oversized postcard is one that measures 11.5 inches by 6.125 inches. Also, the type of stamp you require is the Postcard Forever Stamp.

For a postcard with the standard size, you will only require one stamp at the cost of $0.40. If you have the oversized postcard, you will need one Postcard Forever Stamp plus an additional one-ounce stamp, bringing your expense to $0.58.

If the postcard is larger than 11.5 inches by 6.125 inches, you will require at least three stamps.

### 5. How many stamps do I need for a small envelope?

You only require one stamp for a small envelope. A small envelope measures 9 inches by 6 inches and weighs up to one ounce. In this case, you will only pay $0.58 to send the envelope.

However, understand that you will have to pay more if the envelope measures 6.5 inches by 9 inches. But if the weight is between 1 and 2 ounces, you will have to pay an additional $0.20, bringing your total to $0.78.

### 6. How many stamps do I need for tax returns?

Tax returns have many forms. That means they are heavy and will require additional postage.

However, a Forever Stamp will be enough if the envelope is one ounce or less. Similarly, if you only have 2-3 forms in a regular letter-size envelope, you’ll need a single stamp.

If your tax returns have many pages or you are using a large flat envelope, you will have to weigh it to determine the number of stamps you will require.

For example, your forms plus envelope weigh two ounces. In this case, you will need one stamp ($0.58) plus one additional ounce stamp ($0.20).

Also, if your tax returns forms plus the envelope measures 8.5 inches by 11 inches and weigh one ounce, it means you are dealing with an oversized letter.

Therefore, you will need two regular stamps ($1.16) or one regular Forever Stamp plus three additional ounce forever stamps (overpays $0.02).

### 7. How do I know how many stamps to use?

You will know the number of stamps to use based on your letter’s weight, size, and destination. If you have a package that is less than one ounce, you only require one stamp.

Here is a breakdown for First Class standard size letters:

**2 oz.**– one single two-ounce Forever Stamp or one regular Forever stamp plus one Additional Ounce Forever Stamp or one regular Forever Stamp plus $0.20 miscellaneous postage.**3 oz.**– one single three-ounce Forever Stamp or one regular Forever stamp plus two Additional Ounce Forever Stamps or one regular Forever Stamp + $0.40.

If you have an oversized First-Class letter, here is a breakdown of the number of stamps to use:

**2 oz.**– two regular stamps plus one Additional Ounce Forever Stamp.**3 oz.**– two regular Forever Stamps plus two Additional Ounce Forever Stamps.**4 oz.**– three regular Forever Stamps plus $0.02 stamp or two Forever Stamps plus three Additional Ounce Forever Stamps.

However, you can make a better determination by using the Postage Price Calculator.

### 8. How many Forever Stamps do I need?

The number of Forever Stamps you will need will depend on your package. If your package is one ounce or less, you require one Forever Stamp to send your parcel.

But if the package is between one and two ounces, you will need two Forever Stamps. The number of Forever Stamps increases with the weight and size of your parcel.

But understand that your letter must be of regular shape. In other words, a standard one-ounce letter must be rectangular and not square, rigid, or odd in shape.

Also, an oversized letter must be rectangular, not rigid, and should not contain any item that causes a variation of more than 0.25 inches in thickness.

### 9. How many stamps for an international letter?

The number of stamps for an international letter is the same as that for domestic letters. However, the difference is in the price of mailing the letter.

For example, a letter that is only one ounce in weight will require the Global Forever Stamp. But it will cost you $1.30 to send it internationally.

If your letter is larger than one ounce, you will have to perform additional calculations based on the dimensions and weight of your package.

You will then have to factor in the current rate of the Global Forever Stamp. Once done, you will get the exact number of stamps to use and how much to spend.

### 10. Can I mail a letter to Canada with Forever Stamps?

You require the Global Forever Stamp to mail a letter from the USA to Canada. The stamp costs $1.30 to place on your letter.

However, your letter must be two ounces or less. After two ounces, you will have to add more stamps to cover the price.

You can also use the regular domestic Forever Stamp. However, the price must add up to $1.30.

In addition, since you are sending a one-ounce letter, you will need two Forever Stamps plus additional forever stamps to make up for the differences. That means your letter may have between four and five stamps.

Instead of having many stamps, buying the Global Forever Stamp is more convenient.

### 11. How many stamps can you put on an envelope?

You can put one or more stamps on an envelope. The number will depend on the size and weight of your letter.

For example, if the entire package is only one ounce, then you need one stamp. But if your envelope weighs 3.5 ounces, you require one domestic Forever Stamp, one postcard stamp, and an additional 10 cent stamp.

Ideally, the number of stamps you put on the envelope should match the price of sending the letter. So, for example, you do not have to put a domestic Forever Stamp, postcard stamp, and another 10 cent stamp.

Instead, you can overpay by buying two domestic Forever Stamps, meaning you will overpay the mailing by around 10 cents.

### 12. How heavy can a letter be before it needs two stamps?

A letter only requires a weight of two ounces to have two stamps. In this case, you will have to buy one Domestic Forever Stamp and one 20 cents additional stamp.

Even if you overpay, you will have to purchase two Forever Stamps. If the weight is more than two ounces, expect to add more stamps with each extra ounce.

### 13. What happens if you put too many stamps on an envelope?

You have no limits to the number of stamps you can put on an envelope. The only thing that will happen if you do so is that it will be expensive to send the mail.

That is because you must buy an additional stamp along with the Forever Stamp to ensure its delivery.

A rule you should follow is that the stamp value must meet or exceed the postage. However, you will not receive a refund if the stamps you bought are of excess amount.

However, that is too much wastage. An alternative solution is to determine the entire postage then put enough stamps to cover it.

The number of stamps you require on a parcel when sending it domestically or internationally will depend on factors like delivery timeframe, size, weight, and destination.

If you are sending a postcard, you will only need one stamp. However, that number can increase further if you have an oversized postcard with over two ounces in weight.

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