Key Takeaways
Postcard size affects layout space, readability, mailing costs, and campaign results, with common standard sizes including 4 x 6 inches, 4.25 x 5.5 inches, and 5 x 7 inches used for direct mail and in-store promotions.
- Standard sizes fit most campaigns. They balance visibility, postage cost, and design flexibility, which makes them the default choice for most mailers.
- Larger postcards give you more room. Extra space for images and messaging helps a promotion stand out in a crowded mailbox.
- Smaller sizes keep costs down. They are simple and budget-friendly, which makes them a good fit for short messages, reminders, or event notices.
- Size affects mailing rules and postage. Choosing the right dimensions helps you avoid surprise costs and delivery issues.
- Design should match the size. Adjust text scale, image placement, and white space so the postcard stays clear and easy to read.
Postcards are not just for sending greetings from summer camp anymore. They have become a flexible format for all kinds of promotional and marketing work.
From direct mail to mini-artworks, menus, and event handouts, a well-designed postcard can do real work in your campaigns.
There is data behind that. According to the 2025 ANA/DMA Response Rate Report, direct mail averages a 4.4% response rate, far above email's 0.12%, which is part of why postcards remain a reliable marketing format.
Choosing the right postcard size matters for how well your piece performs, so here is everything you need to know about the dimensions we offer.
The most common standard postcard size is 4 x 6 inches. It fits most budgets and meets the requirements for the First-Class Mail rate, which makes it a strong choice for cost-effective campaigns.
Postcard Dimensions: Overview
Every business has different advertising needs, so we offer a range of postcard sizes to match your message and style. Whether you want something small and simple or large enough to anchor a direct mail piece, there is a size that fits.
While 4 x 6 and 5 x 7 are the popular dimensions, postcards run from as small as 3 x 4 inches to as large as 6 x 11 inches and everything in between. Below are some of the most common sizes:
- 2.75” x 4.25”
- 3" x 4"
- 3” x 5”
- 4” x 6”
- 4.72" x 4.72"
- 4” x 9”
- 4.25 X 6
- 5” x 7”
- 5.5” x 8.5”
- 6" x 8"
- 6" x 9"
- 6.5" x 9.5"
- 6" x 11"
Standard Postcard Size
The standard postcard size, usually 4 x 6 inches, is handy for businesses. Whether you are launching a product, announcing a sale, or keeping in touch with customers, it is the right size for getting a message across.
Note: The standard postcard size in mm: 102mm x 152mm
The compact size keeps postage costs down and makes it easy for recipients to hold onto, whether on the fridge or an office bulletin board.
It is not just for businesses either. Anyone can use it for personal greetings, invitations, or sharing news. It works well for just about anything you want to say, from a quick note to an advertisement.
Common Postcard Uses
The standard 4 x 6 inch postcard gives you enough space for a range of purposes, including:
- Personal Greetings
- Event Invitations
- Real Estate Marketing
- Announcement Cards
- Artwork or Photography Displays
The size works for both personal and professional use. It gives you room to design without being bulky, which makes it the most practical postcard for most projects.
Rack Cards
Rack cards are a promotional format used mainly in advertising and marketing. They are usually printed on sturdy card stock at about 4 x 9 inches, which is sized for the display racks you see in tourist centers, lobbies, and restaurants.
For setup details, see our rack card design tips.
These cards give passersby a quick snapshot of services, attractions, products, or events. The goal is to present key details in a clear, attractive layout.
They pair strong visuals with brief text and often feature business locations, pricing, event dates, or special offers, and can include interactive elements like tear-off sections or QR codes.
Rack cards are common in tourism and hospitality, but they also work well in healthcare, service industries, and retail.
Common Uses
- Spas and Salons
- Hospitality
- Real Estate
- Healthcare
- Fitness and Sport Centers
- Retail and Services
- Restaurants and Cafes
Square Postcards
Square postcards stand out because their shape breaks from the usual rectangle, which hints at a more creative approach.
They are popular with people who want their mail to feel distinct, including artists, designers, and other creative professionals who want a different format for their work.
With four equal sides, square postcards give you a balanced space for your message or your art. If you want to make a bold statement and leave an impression, a square postcard is worth looking into.
Common Uses
Square postcards aren't your everyday kind of card – their unique shape opens up a world of creative possibilities. Here’s how people are using them:
- Social Media Marketing
- Portfolios
- Retail Announcements
- Event Invitations
- Personal Greeting Cards
- Artistic Displays
Medium Postcards
If a standard 4 x 6 postcard does not give you enough room, the 5 x 7 size is a good next step. It gives you more space to spread out your design and fit the details you need without feeling cramped.
Common Uses
A 5 x 7 inch postcard gives you extra room over the standard size, which makes it a go-to when you have more to say or display:
- Event Invitations
- EDDM Postcards
- Holiday Cards
- Real Estate Marketing
- Artistic or Photographic Print Postcards
- Announcements (Graduation, Baby, Wedding, Just Moved, etc)
Large Postcards
Large postcards, usually around 6 x 9 or up to 6 x 11 inches, give you more space than standard or smaller sizes. The extra room is well suited to detailed graphics, longer messages, and bigger calls to action, so your content stands out in the mail.
Large postcards make a bigger impact and leave a stronger impression on recipients. They also work as menus and signs.
Design Tip: Use the extra space to make your call to action impossible to miss, and pair it with high-resolution photography for the strongest effect.
Common Uses
- Marketing Campaigns
- Event Announcements
- Informational Mailers (EDDM postcards)
- Real Estate Marketing Mail
Every Door Direct Mail Postcards
Every Door Direct Mail (EDDM) is a USPS service that helps businesses target specific neighborhoods or areas without needing individual addresses.
It is a good fit for local businesses that want to reach a broad audience within a set geographic area by zip code.
For a full breakdown, see our guide to every door direct mail and the benefits of EDDM postcards.
EDDM postcards usually come in larger sizes, such as 6.5 x 9, 8.5 x 11, 9 x 12, and even 11 x 14 inches, so they stand out in the mail.
Common Uses
- Small Business Promotions
- Event Advertising
- Real Estate Listings
- Service Providers (Plumbing, Landscape, etc)
- Car Dealerships
- Political Campaigns
EDDM lets businesses target a specific audience in a particular area. It works well for building local brand awareness, promoting special offers, and announcing new services or events.
USPS Postcard Size and Rate Options
Several postcard sizes are eligible for mailing, including 4 x 6, 4.25 x 5.5, 5 x 7, 5.5 x 8.5, 6 x 9, 6 x 11, 3 x 4, and 6.5 x 9.5 inches. Different sizes qualify for different USPS rates.
Postcards measuring 4 x 6 inches are eligible for the USPS First-Class Postcard rate. Postcards sizes between 5 x 7 and 6 x 11 inches may qualify for the USPS Standard or First-Class Letter rate.
Mailing Tip: Always confirm current rates and eligibility with USPS before you mail, since postage specs change.
Print Your Postcards With Print Cartel
From a direct mail campaign to a menu, mini-artwork, or event handout, the right size makes your message land.
Print Cartel offers a full range of postcard sizes to match your project, with the quality and turnaround your business needs.
Start your postcard order or reach out with questions before you print. For layout ideas, our postcard design tips can help.
Frequently Asked Questions About Postcard Sizes
What Is the Standard Postcard Size?
The standard postcard size is 4 x 6 inches, or 102mm x 152mm. It fits most budgets, meets the USPS First-Class Postcard rate requirements, and gives you enough space for a clear message, which is why it is the most common choice.
What Postcard Size Is Best for Direct Mail?
For cost-effective campaigns, 4 x 6 inches works best because it qualifies for the First-Class Postcard rate. For more room or higher visibility in the mailbox, 5 x 7 and 6 x 9 are popular, though they may mail at a letter rate. EDDM campaigns typically use larger sizes like 6.5 x 9.
What Is the Largest Postcard Size You Can Mail?
Standard mailable postcards run up to 6 x 11 inches. EDDM postcards go larger, up to 11 x 14 inches, since they follow different USPS rules. Confirm current size limits and rates with USPS before printing, because anything over the postcard dimensions mails at a letter or flat rate.
Do Bigger Postcards Cost More to Mail?
Often, yes. Postcards within the USPS postcard dimensions qualify for the lower First-Class Postcard rate. Once a postcard exceeds those limits, it moves to the letter rate, which costs more. Match your size to your budget and mailing goals before you commit.
