How Many Stamps Do I Need for a Manila Envelope? (USPS)

If you’ve ever sent or received important documents, then you’re familiar with the tan-yellow envelopes known as manila envelopes.

In addition to their distinctive color and shape, these envelopes are the gold standard for official communications, thanks to their durability and wide range of sizes. If you need to send one, and aren’t sure how many stamps to use, then read our guide!

How Many Stamps Do I Need for a Manila Envelope at USPS In 2024?

Smaller sizes (e.g. 5 x 7 and 6 x 9) weighing less than 1 ounce only require 1 Forever Stamp, while heavier envelopes require additional ounce stamps in 2024. Larger manila envelopes (e.g. 9 x 12) are classified as flats, and start at $1.16 for 1 ounce. Two Forever Stamps cover this amount of postage.

If you’re still not sure how many stamps your manila envelope requires, then be sure to keep reading for more useful facts!

Can You Mail a Manila Envelope with One Stamp?

Depending on the size and weight of your manila envelope, you may be able to mail it using only one stamp.

For example, smaller manila envelopes, such as those measuring 5 x 7 inches or 6 x 9 inches, meet USPS’ size requirements for First-Class letter mail.

As long as a smaller envelope like this weighs less than 1 ounce, then it can be mailed using one stamp.

On a separate, but related note, if you want to make sure you can mail your small manila envelopes using only one stamp, then make sure the ones you buy don’t have clasps, string or medallions.

Such items can get caught in USPS’ mail sorting machines, so they are instead hand-sorted. This additional service results in a non-machinable surcharge (currently set at $0.30).

If you have these kinds of envelopes, you’ll either have to purchase special non-machinable stamps (currently priced at $0.88), or pay the difference using a combination of cent stamps.

How Many Stamps Do I Need for a 5×7 Manila Envelope?

A 5 x 7 inch manila envelope is the smallest size offered. As such, these envelopes meet USPS’ requirements for standard-size letters.

Standard-size letters, including 5 x 7 manila envelopes, can be mailed using USPS’ First-Class mail service.

If your 5 x 7 manila envelope weighs 1 ounce or less, you only need one Forever Stamp to cover postage. Forever Stamps are currently priced at $0.58.

If your envelope weighs more than 1 ounce, you will need to attach additional postage.

USPS charges $0.20 for each additional ounce (up to a maximum of 3.5 ounces total). You can purchase additional ounce stamps online or at your local post office.

If the weight of your 5 x 7 manila envelope exceeds 3.5 ounces, USPS will consider it as a large envelope (also called a flat), and it will be priced accordingly.  

How Many Stamps Do I Need for a 6×9 Manila Envelope?

How Many Stamps Do I Need for a 6x9 Manila Envelope? USPS

As with 5 x 7 envelopes, 6 x 9 manila envelopes also fit USPS’ criteria for standard-size letters.

Therefore, they are also sent via First-Class mail service. One Forever Stamp is enough to cover postage, as long as your envelope weighs less than 1 ounce.

If your 6 x 9 envelope weighs between 1.1 ounces and 2 ounces, you’ll need to add an additional ounce stamp (priced at $0.20) to cover the weight.

In a similar manner, if your envelope weighs between 2.1 ounces and 3.0 ounces, you’ll need 2 additional ounce stamps.

If your 6 x 9 envelope exceeds the 3.5 ounce-maximum for First-Class letter mail, then it will be priced as a large envelope/flat.

How Many Stamps Do I Need for a 9×12 Manila Envelope?

This size manila envelope is the most commonly used, as it accommodates standard paper measuring 8 ½ x 11 inches.

USPS classifies envelopes of this size as large envelopes/flats.

Pricing (and the number of stamps needed) depends on the weight of the envelope. Here’s what you can expect to pay for 9 x 12 manila envelopes of various weights.

Weight not over (ounces) Price
1 $1.16
2 $1.36
3 $1.56
4 $1.76

At current rates, you need to attach 2 Forever Stamps to cover the postage of a 1-ounce 9 x 12 manila envelope.

For each additional ounce, you need to add an additional ounce stamp (currently priced at $0.20).

For example, a 2-ounce 9 x 12 manila envelope requires three stamps (2 Forever Stamps and an additional ounce stamp).

A 3-ounce envelope requires four stamps (2 Forever Stamps and 2 additional ounce stamps).

Can I Use Forever Stamps on a Manila Envelope?

While there’s nothing wrong with using Forever Stamps on manila envelopes, metered postage is usually a better option.

Metered postage can be purchased at the post office or via authorized postage meters leased to small businesses.

Not only does metered postage look more professional, but it will prevent you from under or overpaying for postage, and may reduce delivery delays.

If you’re in a bind, and absolutely have to use Forever Stamps on your manila envelope, we recommend using a scale and USPS’ postage calculator tool to ensure that you include the correct amount of postage. 

To know more about USPS stamps, you can also read our posts on how many stamps do you need for a letter, Purple Heart Forever stamps, and 14 USPS stamp types.


To determine the number of stamps you need to send a manila envelope, you’ll need to know the envelope’s dimensions and its weight.

Small and lightweight manila envelopes only require 1 Forever Stamp, while large envelopes require multiple Forever and/or additional ounce stamps.

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Marques Thomas

Marques Thomas graduated with a MBA in 2011. Since then, Marques has worked in the retail and consumer service industry as a manager, advisor, and marketer. Marques is also the head writer and founder of

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