Every Door Direct Mail® Size Requirements

We’ve worked with plenty of customers who were frustrated and confused by the rules surrounding EDDM® sizes. These regulations outline the acceptable shapes, dimensions, and weights your direct mail pieces must be in order to qualify for an EDDM® mailing.

The goal of this blog is to simplify EDDM® size requirements by addressing common questions and points of confusion. We’ve created a handy size checker and compiled all the direct mail dimensions you need to know to ensure your EDDM® pieces are compliant with USPS regulations.

EDDM® Size Checker

If you already know the size and weight of your mail piece and just want to confirm it can mail via EDDM®, try our EDDM® size checker. If you're looking for more detailed information on acceptable EDDM® sizes, keep reading.

To the nearest eighth of an inch (.125″).
To the nearest eighth of an inch (.125″).
To the nearest thousandth of an inch (.001″).
Weigh a stack and divide by the number of pieces.

*See below if you don’t know how to determine the thickness or weight of your pieces.

How to Determine Your Mail Piece’s Thickness

It's easy to measure the thickness of your pieces without a micrometer or other professional equipment. The minimum thickness for EDDM® (0.007″) is around the thickness of 3 sheets of printer paper stacked on top of one another. If you happen to have a ruler, you could also measure out a stack of mail pieces one inch thick and then divide by the number of pieces in the stack to determine the approximate per-piece thickness.

sheets of paper
Minimum thickness for EDDM® is around the thickness of 3 sheets of printer paper.

How to Determine Your Mail Piece's Weight

You may have no idea what the weight of your piece is, but it's pretty unlikely it weighs more than 3.3 oz. To give you a point of reference, our 4.5" x 10.5" Oversized Postcard weights just 0.4 oz. So if you're mailing postcards or brochures, chances are slim that your pieces will weigh more than 3.3 oz. each.

If you'd like to weigh your pieces just to make sure but don't have access to a postal scale, there are a few ways you can do it. Weigh your entire EDDM® bundle on a regular household scale and divide the weight by the number of pieces you're weighing. This allows you to calculate the weight per piece. Or, you can use common household objects as comparison points. For example, a standard deck of 52 cards weighs around 3.3oz without the packaging. So if your piece weighs the same or less than a deck of cards, you're good to go.

Weight comparison between mail piece and deck of cards
Each piece must weigh the same or less than a standard deck of cards without packaging.

EDDM® Size Requirements

The USPS has specific rules regarding the shape, dimensions, and uniformity of EDDM® mail pieces. We’ll review these requirements in detail below.


EDDM® mailers must be square or rectangular. This means you can’t mail oddly shaped pieces like triangles or ovals unless they’re placed in a large envelope. They also must have four angular or finished (rounded) corners. Finished corners cannot exceed a radius of 0.125″.

Example piece with 90 degree angular corner
Example piece with rounded finished corner


You can only mail flats via EDDM®. To be considered a flat, a mail piece must exceed ONE of the minimum dimension requirements in the table below. Flats cannot exceed ANY of the maximum dimensions. All flats must also have a minimum thickness of 0.007″ and a minimum height of 3.5″. If your piece doesn’t exceed one of the dimension minimums and/or exceeds one of the flat maximums, it will be considered a parcel.

Longest Side EDDM Dimensions: Length
Minimum Dimensions > 10.5″ long and 0.007″ thick and 3.5″ high
Maximum Dimensions 15″ long
Shortest Side EDDM Dimensions: Height
Minimum Dimensions > 6.125″ high and 0.007″ thick
Maximum Dimensions 12″ high
EDDM Dimensions: Thickness
Minimum Dimensions > 0.25″ thick and 3.5″ high
Maximum Dimensions .075″ thick

*Please note that the length of a flat is its longest edge, and the height is the edge perpendicular to the length.

If you’re more of a visual learner, check out the diagram below. It displays the minimum and maximum EDDM® dimensions in an easy-to-understand way.

EDDM Size Diagram
Note: All flats must have a minimum thickness of .007” and a minimum height of 3.5”.

Flexibility and Uniformity

If your mailers meet all of the shape and dimension requirements, there’s one final test: your pieces must be flexible (bendable) and uniformly thick. This means you can’t have some pieces that are thicker than others in the same mailing group. According to the USPS Domestic Mail Manual, any bumps, protrusions, or other irregularities cannot cause more than a 0.25″ variance in thickness. In other words, your pieces can’t be lumpy, uneven, or misshapen.


As you can see, there are many specific rules when it comes to the dimensions, shape, thickness, and weight of EDDM® mail pieces. If you find these requirements confusing, you can always work with a professional printer or direct mail company like Mail Shark that’s well-versed in EDDM® sizes. We work with the USPS on a daily basis and offer the following EDDM®-approved products:

  • Standard Menu
  • XL Menu
  • Standard Brochure
  • XL Brochure
  • Standard Flyer
  • XL Flyer
  • Oversized Postcard
  • Jumbo Postcard
  • Colossal Postcard
  • Original Postcard Magnet
  • Folded Postcard Magnet
  • Oversized Scratch-Off Postcard
  • Jumbo Scratch-Off Postcard

To learn more about EDDM® and how it stacks up against other types of mailings, check out our comparison of EDDM® and full-service direct mail. If you’d like to get started on your own EDDM® mailing, get in touch with us today