Which postcard size is right for you?

Postcards are available in any size imaginable and you can’t choose a wrong size. However, there are advantages and disadvantages to certain sizes that you should consider in order to determine which size will best fit your needs. Follow this guide to get the most bang for your buck.


Standard Print Sizes

Majority of print shops across the country offer the same standard size postcards. The reason for this is that these sizes best utilize the sheets of paper that fit the common printing press.


Standard post card sizes

4”x6”, 4.25”x6”, 5”x7”, 5.5”x8.5”, 6”x9”, 6”x11”, 8.5”x11”

If you choose a size that is different from one of these, it’s likely that it will cost you more money. Going with one of standard sizes will allow you to get the most out of your marketing budget.


What These Sizes Mean to the Post Office

How the post office will handle your mail piece and what they will charge you to do so has a lot to do with the size of your postcard. There are three categories that a postcard falls into and each category is treated a little differently. The first category is called “postcard”, the second “letter” and third “flat”. Here is how they are defined in respect to the size since this is our focus:



Minimum Length: 5” Maximum Length: 6”

Minimum Height: 3.5” Maximum Height 4.25”

If you want to choose one of the standard print sizes, the 4”x6” and the 4.25”x6” would both be considered a “postcard” according the post office.

Any card that is categorized as a postcard automatically receives first class service though you could choose to go third class. You would only consider third class in a highly localized mailing because the timing would not differ much and there is likely a good chance for a deeply discounted postage rate of 21.7 cents. Postcards mailing first class will typically be in homes 2-3 days after you deliver them to the post office. Postage will range from 25.1 cents – 34 cents.



Minimum Length: 5” Maximum Length: 11.5”

Minimum Height: 3.5” Maximum Height 6.125”

Standard sizes 5”x7”, 5.5”x8.5”, 6”x9”, and 6”x11” are categorized as a “letter” according to the USPS standards.

When a postcard is categorized as a “letter” you will have the choice of mailing first class or third class. The differences you can expect will be in cost, deliver time, forwarding, how undeliverable pieces are treated and the minimum quantity. For a clear explanation check out our previous blog post, “The Difference Between First Class and Third Class Mail”.


(flats exceed at least 1 of the minimum dimensions)

Minimum Length: 11.5” Maximum Length: 15”

Minimum Height: 6.125” Maximum Height 12”

Standard size 8.5”x11” postcards are categorized as a “flat” according to the USPS standards.


A Postcard that is categorized as a flat will take the longest to be delivered and in most circumstances cost the most. The exception is if you are targeting neighborhoods or saturating specific areas, then there may be an opportunity for Every Door Direct Mail (a USPS service) which can get you postage as low as 15.6 cents per piece. Complete details on a flat can be found at this previous blog post, “The Difference Between First Class and Third Class Mail”.Sizes and their suggested use


Hopefully you now have a good understanding about standard postcard sizes, as well as how the post office will treat them and what they will charge you. With this information you will be able to make an informed decision on what size will best suit your needs. In addition to how the post office will handle your postcard we also have suggestions to what sizes work best for which scenarios. This information is based on years of experience sending postcards and we think it can help you achieve success.

Follow up and Reminders

Sizes that work best: 4”x6” OR 4.25”x6”

These size postcards will cost you the least amount to print and postage is on the lower end of the rates spectrum. However, you won’t have a whole lot of room because of the size but because it’s a follow-up a lot of room isn’t needed. It also arrives quickly because it will be mailed first class.

Make a BIG Impression

Sizes that work best: 6”x11” OR 8.5”x11”

These size postcards will really stand out among the other mail because they will be larger than just about everything in the mailbox. Larger postcards are good to use in the beginning of a campaign to introduce your brand. This way the following mailers will be recognized and benefit from brand awareness.

General Use Card

Size that works best: 5.5 x 8.5

This all around good size has plenty of room and is very cost effective. Compared to a 6 x 9 postcard, a 5.5 x 8.5 will save you 20% in production costs but is only marginally smaller than a 6×9.

Postcards are great mailers that have a long history of delivering positive results. If you’re looking to maximize your current customers spending or are in need of acquire new customers, postcards are a great tool to consider. If you’re interested in learning how postcards can help your business please contact one of our direct mail experts today at 561-393-4722.


Comments are closed.