1. Postcard Dimensions
  2. Every Door Direct Mail (EDDM) Dimensions
  3. Flats and Large Envelope Sizes
  4. Cost-Effectiveness
  5. Reduce Postcard Damage
  6. Outperform Competitors Thanks to the Right Postcard Mailing Size
  7. Help to Create the Most Effective Mail Design
  8. Provoke the Necessary Emotional Response

A Complete Guide on Postcard Dimensions and Direct Mail Sizes

A lot of people like sending nice postcards to wish their near and dear ones a happy birthday or just say ‘Hello from abroad’ when travelling overseas. It’s a wonderful way to surprise a person and show your special care. In such cases, we don’t pay as much attention to postcard mailing size as when direct mail turns into a marketing channel. As soon as mail pieces become a B2B or B2C marketing tool, postcard dimensions begin to matter. Although it may seem that there is only one standard marketing mail, the variations are numerous. Now you have to become proficient in a variety of direct mail sizes, postcard postage rates, and design options.

For instance, you have to carefully consider where on a postcard is the best place for a call to action to make it more noticeable and nice-looking even after the postage. Your design or logo cannot be too large and must be located only in a specific part of a postcard. Moreover, the United States Postal Service has strict standards for zip codes, fonts, addressee information, and spacing. You will need to also take into account that postal services regularly change postcard postage rates for different types of mail pieces.

Direct mail size

Sounds like a challenge? Not necessarily. Thanks to modern direct mail tools and automation, postcard printing and mailing has become easier than ever. You just need to choose the right direct mail size and design. To get a better understanding of what postcard sizes are the most common and might be the best match for your specific direct mail marketing campaign, check this detailed guide.

Postcard Dimensions

A postcard is probably what first comes to your mind when you think about direct mail. Postcards can be used for multiple purposes – from personal communication to marketing promotions – and are among the cheapest types of direct mail. It’s a great option to tell the recipients what they need to know right away. No envelopes or bulky packages.

Generally, the following postcard dimensions are the most common:

4.25” x 5.5”4” x 6”4.25” x 6”5” x 7”6” x 8”5.5” x 8.5”4” x 9’’6” x 9”6” x 11”

direct mail size

What postcard dimensions can be mailed?

In fact, you can use postal services for any of the types mentioned above. Still, it’s necessary to remember that postcard postage rates offered by USPS differ based on several factors, including mail form and dimensions. Mail pieces that qualify for the First Class Mail are cheaper to send than marketing mail. In particular, if a postcard is larger than 4.25’’ x 6’’, it’s already considered a letter size and charged additionally. Also, a postcard must be thicker than 0.007’’ and have a rectangular shape. How do you check the thickness? Use an index card for reference.

Therefore, if you want to cut mail expenditures and use the most cost-effective option, stay within First Class Postcard limitations. Such mail pieces have a lower postcard rate and usually take less time to deliver than other mail.

Yet if you need to attract more attention to your mail campaign, opt for medium (6’’ x 9”), large (6’’ x 11”), or extra-large (6’’ x 12”) mail pieces. Everything depends on your mailing goals and the allocated marketing budget.

Every Door Direct Mail (EDDM) Dimensions

EDDM is a program launched by the United States Postal Service for more affordable postcard postage rates and convenience. You can either create postcard design on your own or use any of USPS’s affiliate vendors for design, printing, or drop-off. The United States Postal Service claims that EDDM is suitable for small businesses that target a certain mailing area. Here are the most common EDDM postcard dimensions approved by USPS:

11’’ x 17’’8.5’’ x 11’’6.25’’ x 9’’4.25” x 11’’

Although $0.18 per EDDM piece is a very good price, apart from specific sizing, USPS imposes a lot of other restrictions.

  • You will need to have a USPS.com account
  • The batch size must be from 200 to 5,000 mail pieces/day per zip code
  • You will need to drop off the mail pieces at the USPS Postal Office
  • You are tied to a mailing route and don’t have many customization options
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Because of these constraints, every door direct mail may not be suitable for entrepreneurs who need flexibility. They should look for a third-party mail service that offers more freedom and creativity. Consider Inkit as your partner to print and mail marketing materials or other mail pieces without any limitations. This direct mail automation software tool offers unlimited batch size and can be integrated with the most popular CRMs to create tailored mailing lists. For example, you can form a target audience based on the demographic factors and preferences, which will make your marketing efforts more effective. Additionally, Inkit supports variable data printing, so you can directly address every recipient implementing a more personalized marketing approach.

Flats and Large Envelope Sizes

First, let’s clarify what mail falls into this category. According to the official page of the US Postal Service, flats comprise newsletters, large envelopes, and magazines. Boxes and tight envelopes filled with boxes aren’t flats. There are also certain requirements regarding flexibility of such mail. According to the standards, 1-inch minimum flexibility is required.

Speaking of direct mail sizes, there are maximum and minimum dimensions defined for flats:


direct mail size

This type of direct mail is an effective option to send catalogs or newsletters with the latest information about your company. You can advertise your services or feature new arrivals and special offers. Of course, to print and mail flats, you will have to allocate more funds than on postcard printing. However, the investment will surely pay off. Note that 42% of recipients read catalogs they receive and 25% flip them through or save for later. These numbers look striking if compared with a 1% email and social media response rate.

How Can You Benefit From the Right Postcard Mailing Size?

For marketers, understanding direct mail sizes and formats, as well as their benefits and limitations, is more than a necessity. It’s a powerful knowledge you can use to distribute your budget more efficiently and boost your direct mail marketing efforts. Since everything exists for a reason, every type of direct mail was also created for a certain purpose. Hence you need to clearly define your goals before choosing any kind of a direct mail piece and estimate its pros and cons. Make sure to pick the right mailing size to get the following benefits:


USPS offers a range of mailing programs for individuals and companies that print and mail marketing materials in large volumes. Every program defines what postcard mailing size, form, or flexibility is allowed. Based on these factors, the cost of the final delivery may significantly vary. Therefore, if you have a limited budget and need to cut expenditures, pay attention to postcard dimensions. Don’t exceed 4.25’’ x 6’’ to fall under the First Class Mail category and benefit from the lowest charges.

If the standard postcard size cannot satisfy your needs, you should find an alternative to the traditional post office. To deliver customized mail of any volume and size, you can use Inkit’s functionality. Thanks to the postcard builder, Inkit allows creating custom designs based on your preferences. Moreover, this tool significantly reduces postcard postage rates with advanced automation. From now on, you won’t have to bother about finding a printing and delivery vendor. Just click the Send button, and your addressees with receive the mail within 3-6 business days for a fixed rate.

Reduce Postcard Damage

Unappealing postcards with scuffs and smudges can undermine the effectiveness of your mail campaign. When mail is processed, it goes through numerous scanners and automated sorters that may leave unappealing marks. Understanding this process, you can better prepare your mail postcards to the future handling. For example, you can decide to use envelopes for large pieces of mail that require extra care. Also, you should meet the minimum thickness to make your mail more durable. To learn more about postcard damage prevention, read this article.

Outperform Competitors Thanks to the Right Postcard Mailing Size

As it was already mentioned, the United States Postal Service has strict limitations for every type of direct mail. They rightfully set such standards to manage the mailing process and support a single system for all mail pieces. Unfortunately, such standardization also makes most mail campaigns trite and plain. Bombarded with flyers from numerous companies, people start paying less attention to the content.

You can use this to distinguish yourself from competitors and be unique. Among the available direct mail sizes, there are always options used less frequently. Analyze their advantages and consider trying them out. Choose a third-party direct mail tool with A/B testing functionality to test small volumes before investing in large-scale printing. It may well be that for your planned marketing campaign, unusual direct mail sizes are more effective than standard postcard size.

Help to Create the Most Effective Mail Design

Before choosing the mail type and size, you have to understand what information, images, or call to action you want to add. This preparatory stage is crucial in picking an optimum option. A small 4’’ x 6’’ postcard cannot always include everything you want. It may be more effective to invest in a larger mail or catalog if it offers a higher ROI and response rate.

Also, remember that postcards approved by USPS must meet stringent requirements. There are specific places for the repecient mailing address, barcode, post office marks, and clean area. Take them into account while creating a mail design and choosing postcard dimensions. Make sure your mail piece looks convincing and stimulates people to purchase your products and service. Once you finish with the mockup, it will be much easier to calculate your expenses and predict the results of the mail campaign.

Provoke the Necessary Emotional Response

Any type of direct mail is an excellent way to connect with your customers on a more personal level. Still, certain formats of mail marketing generate better results since they appeal to certain emotions. For example, catalogs nudge people into making a purchase. Postcards with a strong call to action and a QR code stimulate an immediate response. The recipients promptly take their smartphones and scan the code to follow a URL and get a discount. Also, postcards are more likely to be checked than letter-size envelopes. These and other subtleties are closely related to direct mail sizes, which influence customer expectations. Take time to analyze them and build strong relationships with your target audience.

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By submitting this form, I confirm that I have read and understood Inkit's Privacy Policy.
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