Postcard Size Guide: What Are the Standard Postcard Dimensions
The standard postcard size is 4″ x 6″, the most widely used format worldwide because it qualifies for the lowest USPS postcard postage rate and costs the least to print. USPS-recognised postcard dimensions range from a minimum of 3.5″ x 5″ to a maximum of 4.25″ x 6″. Anything larger is classified as a letter or flat and billed at a higher postage rate. Common mailing sizes extend up to 9″ x 12″ for high-impact marketing campaigns.
Choosing the wrong postcard size is one of the most common and most avoidable mistakes in direct mail. Select a size that exceeds USPS postcard dimensions, and you pay letter-rate postage. Choose a size too small, and your piece gets buried in a stack of envelopes. Pick the right size, and you control your postage class, delivery speed, print cost, and design impact simultaneously.
This guide covers every standard postcard size recognised by USPS, explains how each size affects postage, delivery time, and campaign ROI, and tells you exactly which size to choose based on your marketing objective.
TL;DR
- Standard USPS postcard size is 4″ x 6″, with a permitted range from 3.5″ x 5″ to 4.25″ x 6″.
- Postcards larger than 4.25″ x 6″ are classified as letters; pieces above 6.125″ x 11.5″ become flats and cost the most.
- First-Class Mail rates start around $0.36 per piece and deliver in one to five business days.
- Marketing Mail is cheaper in bulk (200+ pieces) but takes two business days to four weeks to deliver.
- EDDM allows neighbourhood-wide mailing at discounted rates with sizes up to 12″ x 15″.
Key Takeaways:
- Postcard size directly determines deliverability, exposure, and whether your piece blends in or stands out in the mailbox.
- The 6″ x 9″ standard postcard is widely considered the ideal balance of design space, visibility, and cost for marketing campaigns.
- Half-fold and tri-fold formats let you use larger flat sheets while still landing within mailable dimensions after folding.
- Jumbo (6″ x 11″) and oversized (9″ x 12″) postcards drive higher response rates but require careful budgeting and targeting.
Standard Postcard Sizes at a Glance
*Postage rates are approximate and subject to USPS annual adjustments. Verify current rates at pe.usps.com. |
Factors to Consider When Selecting Standard Postcard Sizes
Selecting a postcard size might not sound like the most important element in your direct mail campaign. But it is definitely a choice that you need to make carefully and after considering some related factors. Below are the vital factors to consider while selecting postcard dimensions.
1. Deliverability
A small postcard mailing size is probably not the best option for you if you want all your postcards to be safely delivered. Small postcards can easily get lost in the mail as they are not of the standard envelope size. Hence, postcards should at least come under the standard postcard size, if not larger.
Oversized mail always has the edge over the others due to its extra size and attention-seeking capability. However, there are many other factors that decide whether you need a small, medium, or large-sized postcard.
Furthermore, standard-sized postcards are eligible to be sent through first-class mail, increasing their chances of getting delivered. So, if deliverability matters to you, standard-sized mail is a perfect choice.
2. Exposure
Although the guidelines for US postcard sizes suggest that your mailpieces should not exceed 4.25″ x 6″, a larger postcard is more likely to stand out from the others.
Mostly, companies mail their letters, documents, and marketing materials in the standard size, so your standard-sized postcards might not get the necessary exposure. Many people may also think of it as “junk mail” and discard your postcard even without opening it.
Keeping the exposure and uniqueness element in mind, you should opt for a bigger size. It is inherent that large-sized mail receives more attention than all the other sizes.
3. Message
The message should always be paramount. Basically, it should dictate the postcard size.
- What does your brand have to say?
- Is there any exciting contest coming up, the details of which need to be included?
- How much content do you need to insert in order to communicate your message to the audience clearly?
These things are the key elements to consider while choosing the correct postcard dimensions for your campaign. If your message can be clearly and thoughtfully sent across using a small or standard-size postcard, go for it, this size can get your work done and at the same time also keep your marketing costs under control.
However, you should note that the entire space in a postcard is not meant for your content. The location of the logo, mailing address, trim lines, and keep-clear zones should also be thought of. After these things are added, the remaining space is for you to insert your message, which basically makes your postcard's front side. Hence, you might need a larger size than you think. Fitting too many words on a small postcard can look messy.
4. Design
Words are not the only thing that is added to your custom postcard. A legal postcard size gives enough space for some words and graphics to be put together on a suitable postcard template. Businesses need to include their logo as well. Marketers typically select designs with some images, borders, and overall graphics fitted together in a compact space within which the message is printed.
- Do your words need to be printed in big and bold letters?
- Are there any extra images you need to include?
- Is the message printed as a paragraph or in bullet points?
5. Time
The period we are talking about is the delivery time and the season during which you are conducting a postcard marketing campaign. A big postcard will need to be sent using the USPS Marketing Mail option. This mail option has a longer delivery time than first-class mail, which makes it a difficult choice.
If your postcards are conveying a message regarding offers with short deadlines, select a size that fits within the USPS postcard dimensions so that your postcards can be sent through the faster first-class option. But, if time is not your first priority and getting your postcards delivered after a couple of days or even weeks works for your brand, you can choose a larger size.
6. Cost
Over and above all the above-mentioned factors, you have to select a size that fits your budget. Before making any selections, draft out your budget first. Check whether you can afford to go for the maximum postcard size. If not, what size can fit well?
Companies having a very tight budget can either go for a standard size or use the EDDM option, as it is relatively inexpensive. You can save money by sending in bulk. For large postcards, you can send bulk marketing mail, through which you will be eligible for getting discounted rates. Even if your postcard size does not fit in the USPS postcard dimensions, there are a number of ways to get postal discounts, like pre-sorting and bulk mailing.
USPS Standard Postcard Dimensions: What Qualifies as a Postcard?
The USPS defines a postcard by specific dimensional rules. If your mailpiece falls outside these limits, it is reclassified, and you pay more. Here is what USPS requires for a piece to qualify for postcard postage rates:
Reclassification rule: Any postcard exceeding 4.25″ x 6″ is classified as a letter and charged at letter rates. Pieces exceeding 6.125″ x 11.5″ are classified as flats, which carry the highest postage rates in the standard mail categories. Letter and Flat Size Thresholds
Source: USPS Business Mail 101 — pe.usps.com/businessmail101 |
Regular and Mailable Postcard Sizes
Keeping the USPS postcard dimensions into consideration, there are some of the most commonly used sizes, like the 4″ x 6″ postcards. The most common sizes for sending postcards are:
- 3.5″ x 5″
- 4″ x 6″
- 4.25″ x 6″
- 4″ x 9″
- 5″ x 7″
- 5″ x 8.5″
- 6″ x 9″
- 6″ x 11″
- 8.5″ x 11″
- 9″ x 12″
The 3.5″ x 5″ postcards can be referred to as small-sized postcards because the standard and the most commonly used size starts at 4″ x 6″. Please note that only the first three U.S. postcard sizes from above are considered postcards by the USPS.
All the remaining postcard sizes will be charged more and sent through marketing mail. The USPS also accepts folded postcards as long as they fit within the US postcard sizes' restrictions.
Half-Fold Postcard Sizes
- 8.5” x 6” (folded to 4.25” x 6”)
- 10” x 7” (folded to 5” x 7”)
- 11” x 8.5” (folded to 5.5” x 8.5”)
- 12″ x 9″ (folded to 6” x 9”)
- 12″ x 11″ (folded to 6” x 11”)
Tri-Fold Postcard Dimensions
- 12.75″ x 6″ (folded to 4.25” x 6”)
- 15″ x 7″ (folded to 5” x 7”)
- 16.5″ x 8.5″ (folded to 5.5” x 8.5”)
Different Postcard Sizes Businesses Can Use
1. Small-Sized Postcards
The postcards whose dimensions are 3.5″ x 5″, 4″ x 6″, or 4.25″ x 6″ are all considered small-sized. They are small and have a compact space for your message. The designs are mostly simple and straightforward, without a lot of images and graphics. As opposed to a big postcard, small-sized postcards are very cheap to send. The designing, printing, and mailing costs are low for conducting a postcard marketing campaign using these small sizes.
Moreover, these sizes are well-approved by the USPS to be sent as First-Class Mail postcards. So, you get all the First-Class Mail benefits like mail forwarding or return, priority processing, and low rates. However, small-sized postcards are likely not to stand out from the other mail items that your recipient receives. But, to stay under budget, companies use this size widely.
You can use bright colors and eye-catching designs to make your small postcards stand out. This step makes your postcards impactful while also keeping costs under control.
Do |
Don’t |
| Focus on a single message and call to action | Cram in too much information into a small space |
| Use a strong yet simple headline | Place content or graphics too close to the postcard edges |
| Prioritize readability by using large fonts | Shrink larger images to fit |
| Add QR codes and pURLs instead of lengthy links | Send to customers who require more information or context |
2. Medium or Standard-Sized Postcards
Businesses select some standard sizes like 5″ x 7″ and 6″ x 9″ to give their postcards more exposure. These postcards outsize envelopes and hence have more chances to be noticed by your audience. The medium or standard-sized postcards do not come under the USPS postcard dimensions, which is why you will have to send them using USPS Marketing Mail. You may have to pay more for these postcards and wait longer for them to get delivered, but it is worth it.
Postcards that come under these specifications are more creative, versatile, and noteworthy. The design could be portrait or landscape, depending on your message. Some marketers use poster-like designs for a portrait layout.
However, please remember that the back of the postcard is always landscaped according to the USPS address and mailing guidelines. It doesn't matter if your postcard layout is horizontal or vertical. Standard-sized postcards have enough room to accommodate any design neatly.
Do |
Don’t |
| Use the extra space for negative spacing, imagery, or bullets | Forget to structure the copy well to guide the recipients regarding what to read first |
| Break the message into short sections | Overload with details |
| Maintain a balance of text and images | Use too many colors and fonts for the same postcard |
| Place the call to action in a place where customers can easily notice it |
3. Jumbo-Sized Postcards
They outsize the standard size but are still a step away from being called “oversized.” Usually, postcard dimensions – direct mail size of 6″ x 11″ come under this category. Jumbo postcard sizes offer the same scope for versatility and creativity as the standard ones, but the proportions are relatively larger.
A jumbo-sized postcard is more attention-seeking and is great for designs that need a large space to fit in. If your company wants to advertise using postcards with big images or many words, you can select this size. Marketers can even go for gloss coating to make their postcards even more appealing.
Do |
Don’t |
| Create a well-thought-out visual flow from the top to the bottom | Scatter images and text all around the postcard with no clear layout |
| Use bold imagery to make a strong impact | Leave a lot of white space that makes the extra space redundant |
| Add headlines that summarize the message | Include lengthy messages to fill up the space |
| Make calls to action and contact information easy to locate |
4. Oversized Postcards
9″ x 11″ postcards are considered extra-large. Oversized or extra-large postcards are selected by companies that do not want to compromise on their visibility. The USPS will send these postcards at flat-rate pricing. So the overall costs are really high. In fact, it is the most expensive option that marketers can select. Everything from its design and printing to mailing will cost you a lot. But, oversized postcards are capable of attracting more responses and engagement than all the other sizes.
Hence, by proper planning, you can distribute costs smartly and get an increased ROI. If your budget can accommodate the costs of conducting a campaign with oversized postcards, you should definitely consider going for it.
Do |
Don’t |
| Leave adequate margins to make the design look aesthetic | Add more information than the customers can digest |
| Use sections to not overwhelm readers | Use a large envelope to enclose the postcard; it is best to send it as a self-mailer |
| Add bigger images to use the space to your advantage | Make the design too cluttered or unstructured |
| Place the calls to action strategically | Send these postcards to everyone; only target long-term customers or hot, high-ticket prospects |
Also Read: Note Card PrintingPros, Cons, and Top Use Cases to Consider Before Selecting the Postcard Size
Postcard Size |
Pros |
Cons |
Best Used for |
| Small |
|
|
New product or service promotions, seasonal sales offers, high-volume marketing campaigns, event announcements & invites |
| Medium/ Standard |
|
|
Customer milestones, employee appreciation, referral programs, brand introduction, welcome to the neighborhood messages |
| Jumbo |
|
|
Seasonal marketing, high-ticket client acquisition, retail launches, luxury marketing |
| Oversized |
|
|
High-impact events, company milestones, significant brand moments, premium campaigns, high-value customer retention |
EDDM Postcard Sizes
Before talking about the legal postcard sizes under the EDDM option, let us discuss a little about what exactly is EDDM. It stands for Every Door Direct Mail. As the name goes, it means sending direct mail items to every household in a particular locality or ZIP code area. This program is introduced by the USPS so that companies can conduct direct mail campaigns without having a mailing list. You can select the locality or ZIP code of your choice, and the USPS will deliver your postcards to every house in that area.
The EDDM option works great for businesses that have a limited budget. Furthermore, it is also a good option for geographic targeting.
Also Read: Business Postcard Ideas for Better MarketingEDDM does not fall under the First-Class Mail and Marketing Mail categories. It is a separate service, and the USPS offers discounted rates for this program. Just like the other mail options, there are specific postcard mailing sizes under EDDM also. Your postcards should be at least 6.125″ in height or 10.5″ in length on one side.
The standard postcard dimensions for EDDM should not exceed 12″ x 15″. If your postcard sizes don't fit within these USPS dimensions, you cannot send your postcards using the EDDM option. The thickness should be between 0.0007″ and 0.75″. The per-piece weight should not be more than 3.3 ounces. The most popular postcard sizes for EDDM are 4.25 x 11″, 6.25″ x 9″, 6.25″ x 11″, 6″ x 12″, 8.5″ x 7″, 8.5″ x 11″ and the oversized 12″ x 15″. You can select from these sizes as per your requirements and budget. You can select from these sizes as per your requirements and budget.
Although the USPS rates for sending any EDDM postcards are the same for all sizes, printing and paper cost differs. Companies can contact USPS-affiliated printers to get the printing done, other local printers, or a print and mail automation platform like PostGrid.
Differences Between First-Class Mail and Marketing Mail Options to Send Postcards
First-Class Mail
In terms of speed, First-Class Mail is the fastest option to get your postcards delivered. It delivers local mail in one to three business days, whereas national mail is delivered within three to five business days. As discussed above, if the timing is important to you, it is advisable to stay within the standard postcard size and send via first-class mail.
All first-class rates are dependent on the weight and size of your mailpieces. For availing of the lowest first-class rate, your postcards should weigh less than an ounce. The rates go up with the increase in weight. The maximum postcard size to be sent through first-class is 4.25″ x 6″. Anything larger than this size or thicker than 0.016″ is considered as a letter and charged accordingly. Rectangular, standard-sized postcards cost a minimum of $0.36 per mailpiece.
Marketing Mail
Formerly called “standard mail,” this option is created by the USPS to specifically tend to the marketing needs of businesses. It is also sometimes referred to as bulk mail. Bulk rates can be availed by sending out a minimum of 200 mailpieces.
To deliver locally, the USPS takes about two to five business days. National mail can take up to one to four weeks for delivery, so you might have to opt out of this option for time-sensitive mailings. The lowest marketing mail rate is for postcards weighing up to 3.3 ounces. After that, the rates keep increasing gradually. Bulk mail does not have services like mail forwarding and return, but you can pay extra for them.
Moreover, the marketing mail option is used for postcards that do not fit in the USPS postcard dimensions. They are charged as letters, which is relatively more than postcards. But, you can avail of bulk rates and stay within your budget. Postcards that exceed the maximum postcard size of 4.25″ x 6″ are all sent via marketing mail.
What is the Best Postcard Size for Cost-Effective Mailing?
A small postcard is the most cost-effective and compact option for straight-to-the-point designs. The USPS recognizes it as the traditional postcard. It measures anything between 3.5” x 5” and 4.25” x 6”. If your postcard falls within this size, you can use First-Class Mail at a lower postage cost than Marketing Mail.
Using First-Class Mail will make your postcards move much faster through the postal system and even forward them if the recipient has moved to a new address. These postcards require you to buy those 4.125’’ x 9.5’’ envelopes. This postcard size might not stand out as much as the large ones, but it is the most economical option.
Ideal Postcard Size for Marketing
Standard 6” x 9” postcards are ideal for direct mail marketing campaigns. They offer more design space, visibility, and versatility than smaller postcards. Many businesses prefer these postcards for designing impactful visuals, encouraging messages, and precise calls to action. The versatility allows us to experiment with different marketing purposes, such as product promotions, event announcements, or brand awareness campaigns.
The larger size allows you to grab consumer attention for better engagement and response, and gives you more visibility in the mailboxes than your miniature counterparts. You can combine design creativity, impactful messaging, and compelling calls to action to increase the results of standard postcard direct mail marketing campaigns.
Postcard Design Checklist to Follow in 2026
According to the marketing guru Ed Mayer, 20% of your campaign’s success depends on the creative. Here is what you should keep in mind when designing your postcards, irrespective of the size:
Don’t Overcomplicate It
Less is more when it comes to designing a postcard. The more information or design you include, the more effort your recipients will need to process it. It’s always better to maintain a balance between the amount of design and text you add to your postcards. Directly discuss what you offer instead of cramming the design with unnecessary images and text.
Use High-Quality Original Pictures
Pictures are everything in postcard designs. A high-quality original image is necessary to grab the recipients' attention instantly. This image must be real instead of stock images to convey your message and emotionally connect with your audience. You also need to be very mindful of the placement and size of the image. The picture must break up large blocks of text in the postcard to help readers grasp the information without getting overwhelmed.
Use an Attractive Headline
The headline will be the first text that your customers notice. Use bold and benefit-driven headlines to encourage users to take immediate action. It must spark interest and make them curious to read more. A well-written headline can evoke a sense of urgency, excitement, or curiosity among the recipients.
Use Bleed to Extend Colors
Your postcards should have bleed to ensure they appear more polished and convey professionalism. Ask your printer to extend the colors beyond the cut line to provide complete coverage without unwanted edges. They can easily extend the print by at least 0.25 inches beyond the trim size of the postcard.
Mention the Benefits Instead of Features
Your recipients aren’t interested in reading technical jargon. They are more curious to know how your offerings can benefit them. Postcards have limited space to mention anything. Focus on the benefits to develop an instant emotional connection with the recipients and encourage them to take action.
Implement Creative Use of White Space
Recipients never welcome a cluttered postcard; it makes it harder to comprehend the key information and core message. Such practices also risk your business appearing unprofessional and less credible. We must use sufficient white space to break up text and design elements within the postcard to make scanning easier for the recipient. A generous amount of spacing makes the headline, body text, and CTA stand out.
Select a Readable Typography
Many brands go crazy by experimenting with the typeface in their postcards. It breaks the visual clarity and clutters the space, making comprehension difficult for the recipients. The font of your choice must be easy to read, complement your overall design, and align with your brand identity. Moreover, a test by Toner Buzz proved that you can reduce printing expenses by up to 77% by selecting the right font.
Add a Single and Impactful Call to Action
The CTA of your postcard must be easy to understand and visible in the design. Use action verbs and bold fonts to improve its readability and impact for the recipient. It will encourage them to take immediate action instead of throwing the mailpiece into a bin or storing it for later.
Add Interactive Tracking Elements
Traditional direct mail is hard to track and measure. Modern technologies like QR codes and Personalized URLs allow you to get genuine insights about the recipients by navigating them to your online portals. Businesses often determine the response rate, online interactions, and ROI to optimize their future campaigns.
Advantages of Selecting the Right Postcard Size
Other than saving your money, time, and effort, there are a lot of other advantages to making the right choice for your postcard size.
1. Helps in Creating the Perfect Design
By selecting the perfect postcard size for your direct mail campaign, you are helping your designer create the right design for your postcards. This design should justify your message, CTA, and offers. Everything should look distant from one another, and the design should not be messy. If your message is long and you select a small US postcard size, the message will have to be fitted on your postcard in a congested manner. Conducting a direct mail campaign and sending out such messy-looking postcards is an absolute waste of your time and money. Marketers should know what a postcard is and how it is supposed to deliver messages compactly.
2. Ensures On-time Deliverability
Making a smart choice for your postcard size can help ensure on-time delivery that justifies your campaign's objectives. Different direct mail campaigns are designed and conducted for various reasons like promoting a product launch event, introducing new services, informing audiences about discounts, offers, contests, etc. Some of the postcard marketing campaigns are held for general brand awareness and increasing visibility. However, some of them are meant to drive conversions quicker by using special coupon codes and offers valid for a very short time. The “Urgency creation” is a marketing strategy used by many companies to receive faster responses. Hence, if your company is sending out postcards with this motive, selecting the right postcard size can help send it faster through first class.
3. Creates a Personal Connection
Choosing the perfect postcard size can help make your postcards attractive and attention-seeking. Sending such postcards in the mail to your target customers can induce a special and emotional bond between them and your brand. An appealing mailpiece works better than mailpieces that aren't designed well. Your postcards can get your message across with more clarity and meaning by using the right postcard dimensions – direct mail size. Postcards should be thoughtful, impactful, and prompting, and these things are not possible without making a smart size choice.
4. Boosts Responses
If you want to get the desired number of engagements and responses, it is recommended that you select the right color combination, offer, CTA, message, template, and size. All of these things matter. You can send out a small number of postcards with different variations to test all the combinations' performance. The right postcard size used for the right type of layout and message can definitely attract more responses and boost engagement levels.
How Businesses Send Postcards at Scale With PostGrid
| Choosing the right postcard size is step one. Executing a campaign printing, addressing, sorting, and mailing hundreds or thousands of pieces is where most businesses hit a wall. Traditional print shops require manual file uploads, proofing cycles, vendor coordination, and separate tracking. For teams running recurring campaigns or CRM-triggered mailings, that workflow breaks down fast.
PostGrid's Print & Mail API automates the entire postcard fulfillment workflow. Upload your mailing list, select your size, submit your design, and PostGrid handles printing, address verification, USPS sorting, and delivery tracking, for any size from a 4″ x 6″ postcard to a 6″ x 9″ marketing mailer. Real-World Use Cases by Industry
Unlike print shops (which sell design and print) or campaign agencies (which manage your sends as a service), PostGrid is a software platform. Your team or your developers can trigger postcard sends programmatically, integrate with existing CRM and marketing automation tools, and track delivery status from a single dashboard. Sign up now to automate your next postcard campaign. |
FAQs
What is the Best Postcard Size to Mail Internationally?
Though you can mail any size to any country, it is best to stick to small or standard-sized postcards to ensure they reach the destination without hassle. Also, it is a great way to keep your global postage to a minimum.
Can I Set Up Campaigns for Different Postcard Sizes?
Yes, you can send postcards of different sizes. All you have to do is create separate orders with your custom needs, but select the same shipping date.
Is It Safe to Send Postcards Without Envelopes?
Yes, you can send postcards without envelopes safely as long as you don’t print any sensitive client or brand information on them. Please ensure you don’t add any personal details to the postcards that can lead to a data breach. Also, use plastic coating and thick-weight postcards to protect them against wear and tear during transit.
