The Ultimate Guide to Postcard Sizes

The Ultimate Guide to Postcard Sizes

Postcards are one of the most effective ways to send your target audience a direct mail campaign. The reason they’re so effective is because of how simple a postcard is. The recipient does not have to open an envelope, making it much easier to get your message seen. However, what isn’t so simple is deciding which of the postcard sizes is right for you. To complicate matters even further, the United States Postal Service has different postage rates depending on which size postcard you would like to send. There is a lot of information out there about postcards, but we have created the ultimate list of postcard sizes with their rates to help you see things clearly.

What is a postcard according to the USPS?

It may seem silly to define what a postcard is, but it is vital to understand just what the USPS says a postcard is.

The USPS describes a postcard as:

  • Rectangular
  • At least 3-1/2 inches high x 5 inches long x 0.007 inch thick
  • No more than 4-1/4 inches high x 6 inches long x 0.016 inches thickMinimum Postcard Size

According to the official USPS guide, “If your mailpiece does not meet the dimensions above, then the Postal Service considers it a letter, and letter-size postage is charged.” So what does that mean exactly? You will be charged more per postcard if you exceed these dimensions.

Before we jump into the pros and cons of each postcard size, we want to clarify the difference between the two main classes of mailing (first class mail and marketing mail) and the two main size classifications (postcard and letter).

Mail Classes:

The USPS has two different kinds of mail classes for postcards. These classes determine when your target audience will receive your mailer and how expensive each piece will be for you.

  • First Class Mail – Offers a quicker delivery time, typically 3-5 business days, but is typically more expensive.
  • Marketing Mail – Offers a slower delivery time but is generally less expensive.

Mail Sizes:

The USPS has two different sizes they use to classify their postcards. These sizes are made by USPS. (Yes, we even get confused by them from time to time.)

  • The “postcard” technically defined by the USPS is at least 3.5″x5″ but no more than 4.25″x6″.
  • All other sizes are technically “letter-sized”. These are larger than 4.25″x6″ and not larger than 6.125″x11.5″.

Standard Postcard Size

The standard postcard size is 4″ x 6″, which is a typical rectangle mailer. The standard postcard size falls within the USPS’ regulations for a postcard size. By default, the size classifies your piece as First Class Mail.

With the 4″x6″ postcard, you get the most affordable direct mail option. Not only do you get cheaper postage options and more affordable printing costs, but you also get a faster delivery time than if you were to use Marketing Mail.

Standard Postcard Size Example

Medium Sized Postcard – The Best of Both Worlds

The next common size we see come through our shop is what we call a “medium-sized” postcard. This postcard measures generally between 6″x8″ to 6″x9″.

This is a great option for those looking to find a balance between cost and effectiveness. The obvious benefit here is there is more room to showcase your design. However, the cost will go up in both print and postage. Due to the USPS’ definition of a postcard, this would classify as a “letter”.

If you want to maximize your budget while using the 6″x8″ postcard size, we recommend ordering over 200 pieces and using Marketing Mail.

Medium Post Card Example

Jumbo Postcards

The last size we often see printed on our presses is what we call a “jumbo postcard”. These postcards are much larger than the average postcard. These postcards can be a maximum of 6″x11″. If you go any larger than this, your direct mail campaign will no longer be classified as a postcard.

These large postcards are not for everybody, but they do serve a purpose to those looking to leave a big impact on their audience. They can also convey a larger message that would look too crowded on the other sizes.

The 6″x11″ postcard, however, is the exact same postage cost as the medium size. The only difference is that the price in printing will go up for a larger piece.

Large Postcard Example

EDDM Postcard Sizes

To complicate the postcard sizes and definitions further, the USPS has regulations for their Every Door Direct Mail (EDDM) service. EDDM is another mail classification, like First Class and Marketing Mail, that allows you to pick a mailing route or zip code as your audience instead of crafting a mailing list.

If you are using EDDM as your method to send your direct mail campaign, the USPS allows you to go up to 15″x12″. However, we usually recommend going to a maximum of 11″x14″ to get the most visibility with your campaign.

Using EDDM is generally cheaper than First Class and Marketing Mail, and you can print on a larger postcard.

EDDM Postcard Size

Of course, you can get custom postcard sizes to fit the needs of your marketing campaign.

You can see just how confusing postcard sizes can be. On top of the already confusing sizes the USPS lays out, your designer has to know the exact dimensions of where the postage goes and the address block.

We get just how overwhelming direct mail is. We have to relearn a lot of the rules and regulations the USPS implements each year. We’re here to make your life easier so you can see the huge rewards of a direct mail campaign.


Downloadable Postcard Size Reference 

Ultimate List of Postcard Sizes Graphic

Just right click the image and save it to your desktop for later.


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August 14, 2019

(4 min. read)

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