Liz Grinnell by

Can I Mail This Size Postcard? A Guide to Direct Mail Postcard Sizes.


Direct mail is a great marketing tool to utilize within your marketing strategy, but when it comes to printing a postcard, size does matter!

When you’re looking to utilize direct mail in a marketing campaign or promotion, one of the first things you’ll need to know are the size options for your postcard. The images below will give you the dimensions that are the most common, and that will still allow you to meet all the mailing requirements and get the best USPS rate.


Postcard Sizes

Market Mail and True Postcard Sizes








True postcard sizes (3.5×5 to 4.25×6) are eligible to mail at the USPS First-Class postcard rate.

Oversized postcards (3.5×5 to 6.125×11) qualify for Market Mail (Standard), the Market Mail Nonprofit Rate, or First-Class.


EDDM (Every Door Direct Mail) Sizes

EDDM Mailing Sizes









EDDM postcards must exceed one of the following:

10.5″ in length

6.125″ in height

.75″ in thickness

How Can You Mail Your Postcard?

There are three main ways you can mail a postcard: First-Class Mail, Market Mail (standard and nonprofit), and EDDM.

  • First-Class Mail is the best option when looking to get your postcard into someone’s hands quickly! Postal delivery goals are 1-3 days, and this option will provide you with return service for undeliverable pieces.
  • Market Mail (standard and nonprofit) is a cost-effective way to reach your direct mail audience if timing is not critical (postal delivery goal is 2-15 days). Return services are not included, but can be added as an endorsement for an additional charge per piece.
  • EDDM (saturation mailing) is a great option when you’re looking to mail to everyone in a mail route or zip code. It is also a great way to reach all residential and business addresses or residential only addresses in a given area. EDDM is a process used by the post office for flat-sized pieces. Note: If there is a Market Mail Letter size that would work better for a specific promotion or event you’re doing, there is a saturation letter option that allows you to mail to “everyone” and get those awesome saturation rates. Contact us or your mail house for details!


Giving direct mail its moment to shine in a marketing campaign gives you the opportunity to make a powerful first impression with a new or existing target market audience. There are many cost-efficient ways to reach potential customers, but you’ll want to make sure you’ve checked all the boxes. The size and professional design of the postcard are essential in making it stand out. So get those creative juices flowing and make your direct mail piece one to remember!