Standard Postcard Size: What is the Standard Size?

Making postcards can be personal and profitable. Of course, if you want your postcards to ship through the mail, then they'll need to fit into one of the standard postcard sizes and conform to the USPS postcard size guidelines. If you're ready to start your postcard design, you'll want a collection of the standard postcard sizes, then decide which is best for your project and artwork.

What are the standard postcard sizes, and what makes them mailable? Let's dive right in:

The standard sizes for postcards

When it comes to postcards, there are actually two size categories. The first is the postcard size, which costs a little less to send. The second is the letter-size, closer to the size of a sheet of paper and charged at normal letter-sized mail prices. Both can be mailed as a single layer of cardstock, however, so are considered official postcard sizes.

First-Class Mail Postcards:

  • 4x6"
  • 4.25x5.5"
  • 4.25x6"

First-Class Letter / Oversized Postcards:

  • 5x7"
  • 5.5x8.5"
  • 6x9"
  • 6x11"

If you're curious, 4" x 6" is the classic postcard size for travel and art postcards found in gift shops. If you are designing commercial mailers, consider the ideal standard size not only to mail, but to get your clients attention and offer value. Both commercial mailers and flyers favor the larger sizes, while artistic cards and collectible postcards favor the smaller standard sizes.

Once you decide your postcard standard size to start with, a graphic designer program like CorelDRAW can make it easy to create your postcard layout and print a two-sided card with beautiful art on one side and the necessary postal design on the other.

USPS rules on postcard sizes

When you send a postcard in the mail, it travels through the USPS (United States Postal Service) and their mail-sorter machines. To make sure your postcards survive the machines and are stamped the right amount, it helps to know USPS's absolute rules on postcard size, including card thickness. Here's what they have to say:

"To qualify for mailing at the First-Class Mail postcard price, it must be:

  • 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 thick

If your mailpiece does not meet the dimensions above, then the Postal Service considers it a letter and letter-size postage is charged." -USPS Sizes for Postcards

As you can see, there is both a minimum size and maximum size for postcards. For reference on thickness, USPS mentions that card-stock is thick enough to mail. A typical business card is only a little thicker at 0.009. Metallic cardstock falls around 0.013 and only embossed wedding menus approach the 0.016 limit. Keeping this in mind, it should be easy to choose a cardstock ideal for your postcard thickness.

Defining postcard height and width

Which way is length and which is width for a postcard? The USPS helps us define the dimensions of a card as well. This may seem silly but it depends on how the mail sorter machines work. For postcard dimensions, the length is always parallel to the address lines, and the height is perpendicular to the address.

Can you print a "Portrait" postcard? Absolutely. Your art can face any direction you want. However, the back of the card will still need to align so the address is along the longest side.

Designing postcards with CorelDRAW

Here at CorelDRAW, we are proud to support a vast community of artists, from hobbyists to graphic designers, to artistic visionaries in any medium. If your current project involves designing and printing postcards, let us streamline your process with excellent tools for artistic creation, document design, and detailed printing. Your postcard design awaits!

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