What Size Are Postcards? Standard Dimensions Explained

Postcard Sizes at a Glance

The standard postcard size is 4" x 6", which is the most common format used for direct mail, event invitations, and promotional campaigns. But postcards also come in 4.25" x 5.5", 5" x 7", 5.5" x 8.5", and 6" x 9" options. Your choice depends on your message, mailing budget, and how much visual real estate you need. 4OVER4 offers all of these sizes across 60+ paper types, so you're never boxed in.

How Big Are Postcards, Really?

If you've ever asked "what size are postcards?" the answer isn't one number. It's a range. The standard postcard size of 4" x 6" works for most everyday mailings, but larger formats like 5" x 7" or 6" x 9" give you room to make a bigger impression. Picking the right size affects everything from postage costs to design layout to how your recipient responds.

This guide breaks down each postcard size, when to use it, and how to set up your files so nothing gets trimmed off. Whether you're sending a thank-you note or a full-color promo mailer, you'll find the right fit here. Grab a head start with 4OVER4's Design Templates, add a scannable link using the QR Code Generator, and check out how to Earn Coins toward your next print order.

Postcards

Starting from $16.48

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Here's a look at the postcard products available at 4OVER4 to get you started:

Direct Mail Postcards

Starting from $89.68

Premium Direct Mail Postcards Ready to Print

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Standard Postcard Size and Every Other Option You Should Know

The standard postcard size is 4" x 6". It's the format most people picture when they think of postcards, and it's the one USPS considers a "standard" mailer. That means you get the lowest postage rate. It's compact, easy to design, and fits neatly in a mailbox without folding. If you're running a high-volume direct mail campaign on a budget, this is your go-to.

But 4" x 6" isn't the only game in town. Let's walk through every common postcard dimension so you can pick the one that actually fits your project.

4.25" x 5.5" - The Compact Card

This size matches a standard A2 envelope opening. It's popular for personal correspondence, RSVP cards, and small event invitations. The compact footprint keeps costs low and works well when your message is short and sweet. Think appointment reminders, thank-you notes, or save-the-dates.

Because it's slightly smaller than the standard 4" x 6", it feels more personal. Less like advertising, more like a note from a friend. That's a big deal when you want your mail to actually get read instead of tossed.

4" x 6" - The Standard

This is the workhorse. The 4" x 6" postcard qualifies for USPS First-Class Mail postcard rates, which keeps your per-piece mailing cost as low as possible. It gives you enough room for a strong headline, a single image, and a clear call to action on the front, plus contact details and a short message on the back.

Real estate agents use this size for "just listed" mailers. Restaurants use it for seasonal menu promos. Nonprofits use it for donation appeals. It's versatile because it doesn't try to do too much. One message, one action, done. If you're also creating other print materials for your campaign, check out our How To Make Flyers guide for complementary pieces.

5" x 7" - The Sweet Spot

Need more room than 4" x 6" but don't want to jump to a large-format piece? The 5" x 7" postcard is the middle ground. You get roughly 40% more printable area compared to the standard size, which means bigger images, more copy, or both.

This size is a favorite for event invitations, product launches, and photo-heavy designs. Photographers love it because the proportions show off images beautifully. Retailers use it when they need to feature multiple products on one card. It still qualifies for standard letter-rate postage when mailed without an envelope, though you'll pay more than the 4" x 6" postcard rate.

"We switched from 4x6 to 5x7 postcards for our gallery opening invitations and the response rate jumped noticeably. The extra space let us feature the artwork front and center."

- Dana K., Gallery Director

5.5" x 8.5" - The Half-Page Powerhouse

Exactly half of a standard letter-size sheet. The 5.5" x 8.5" postcard gives you serious design real estate. It's large enough to include a small map, a coupon, detailed product info, or even a mini menu. This size stands out in the mailbox because it's noticeably bigger than what most people receive.

Direct mail marketers often choose this size when they want the impact of a flyer with the simplicity of a postcard. No envelope to open, no folding, just a bold piece that demands attention. If you're pairing postcards with other collateral, our How To Fold A Brochure guide covers the companion piece.

6" x 9" - Maximum Impact

The largest common postcard size. At 6" x 9", you're working with a piece that's hard to ignore. It dominates a stack of mail. You can fit multiple images, longer copy, tear-off coupons, or even a perforated business card section.

This size is popular for grand openings, major sales events, and political campaigns. The trade-off is higher postage (it mails at the letter rate, not the postcard rate) and higher printing costs per unit. But when you need maximum visibility, 6" x 9" delivers.

Choosing the Right Postcard Size for Your Project

Size isn't just about how much space you have. It affects three things: postage cost, design impact, and recipient behavior.

For high-volume direct mail where cost-per-piece matters most, stick with 4" x 6". You'll save on both printing and postage. For invitations and announcements where you want the piece to feel special, go 5" x 7". For sales promos where you need room for details, product images, or coupons, 5.5" x 8.5" or 6" x 9" makes sense.

Think about what happens after delivery too. A 4" x 6" card might get pinned to a fridge. A 6" x 9" card might get propped up on a counter. The size you pick shapes how people interact with your piece long after it arrives. For more print project guidance, visit our Faq Hub.

File Setup and Bleed Requirements for Each Postcard Size

Getting your file dimensions right is the difference between a clean print and a card with awkward white edges. Every postcard needs bleed - that's extra image area beyond the trim line that gets cut off during production. Standard bleed is 0.125" (1/8 inch) on each side.

Document Sizes With Bleed

For a 4" x 6" postcard, your document should be 4.25" x 6.25". For a 5" x 7" postcard, set up your file at 5.25" x 7.25". For a 5.5" x 8.5" postcard, that's 5.75" x 8.75". And for 6" x 9", your document needs to be 6.25" x 9.25".

Keep all important text and logos at least 0.125" inside the trim line. This "safe zone" prevents your content from getting clipped. Set your resolution to 300 DPI and use CMYK color mode for accurate color reproduction.

Common Design Considerations by Size

Smaller postcards (4" x 6" and 4.25" x 5.5") work best with a single focal image and minimal text. Don't cram too much in. Larger sizes (5.5" x 8.5" and 6" x 9") can handle more complex layouts, but still need clear visual hierarchy. One dominant element, supporting details, and a clear call to action.

If you're working with other print formats alongside your postcards, you might find our How To Make Envelopes guide helpful for coordinating sizes. And for keeping your stamp collection tools in shape, here's a handy guide on How To Clean Rubber Stamps.

USPS Mailing Requirements by Postcard Size

The United States Postal Service has specific rules about what qualifies as a "postcard" for mailing purposes. To get the cheapest postcard rate, your piece must be:

• Minimum: 3.5" x 5" (anything smaller won't be accepted)
• Maximum for postcard rate: 4.25" x 6" and no thicker than 0.016"
• Rectangular with a length-to-height ratio between 1.3 and 2.5

Anything larger than 4.25" x 6" still mails fine, but at the First-Class letter rate instead of the postcard rate. That's an important distinction if you're mailing thousands of pieces. A few cents per card adds up fast at scale.

For pieces that go beyond standard postcards, you might also want to explore how to create Custom Magnets Faq as an alternative mailer format that recipients keep even longer.

Paper Weight and Thickness by Postcard Size

Size and paper stock work together. A flimsy 6" x 9" postcard feels cheap. A rigid 4" x 6" card feels premium. Here's how to match them.

14pt cardstock is the standard for most postcards. It's sturdy enough to survive the mail without bending and thick enough to feel like a real card, not a flyer. Think of it as slightly thicker than a cereal box panel.

16pt cardstock adds noticeable heft. It's about the thickness of a credit card. This works well for 5" x 7" and larger sizes where you want the piece to feel big. Great for invitations and premium brand communications.

32pt ultra-thick stock is a statement. It's roughly 3x the thickness of a standard business card. At this weight, even a 4" x 6" postcard feels like a luxury item. Ideal for VIP invitations, high-end brand promos, or any time you want someone to pause and pay attention.

"I ordered 32pt postcards for our boutique's holiday sale and clients kept telling us how nice they felt. Several people brought the card into the store weeks later - they'd kept it on their desk."

- Marcus L., Boutique Owner

4OVER4 carries all of these weights across every postcard size, plus specialty options like kraft, linen, and pearl finishes. Here are some real customer designs and ready-to-use templates to help you visualize your project:

Blank Templates

3D Lenticular Postcards Banner Stands

Sizing Mistakes That Ruin Postcard Projects

The most common mistake when figuring out what size are postcards? Ignoring bleed entirely. Designers set up their file at exactly 4" x 6" with a background image running edge to edge, then wonder why there's a thin white border after printing. Always add 0.125" bleed on every side.

Second mistake: choosing a large size without checking postage rates first. A client designs a gorgeous 6" x 9" postcard, prints 5,000 of them, then discovers postage costs doubled compared to the 4" x 6" they assumed they'd be paying. Do the math before you commit.

Third: placing text too close to the edge. Even with proper bleed, cutting has a small tolerance. Keep text at least 0.125" inside the trim line. 4OVER4 provides free proofs so you can catch these issues before they become expensive problems.

Finally, don't forget USPS address placement rules. The right half of the back must be reserved for the address, postage, and barcode on mailed postcards. Design your back layout accordingly.

Postcards Worth Printing at 4OVER4

Now that you know what size are postcards and which dimensions fit your project, it's time to pick a product. 4OVER4 prints standard Postcards in every size we've covered, from 4" x 6" all the way up to 6" x 9". Want something that really stops people mid-sort? Check out 3D Postcards for a lenticular effect that adds motion and depth to your design.

Here are the available products, current pricing, specs, and what other customers are saying:

Free Design Templates

Real Estate postcardReal Estate Agent Postcard

Your Postcard Size Questions, Answered

What is the standard postcard size for mailing?

The standard postcard size is 4" x 6". This is the most widely used format and qualifies for the lowest USPS postcard postage rate. Your piece must be between 3.5" x 5" (minimum) and 4.25" x 6" (maximum) to qualify for that rate. Anything larger mails at the First-Class letter rate.

How big are postcards compared to regular paper?

A standard 4" x 6" postcard is about one-quarter the size of a letter-size sheet (8.5" x 11"). A 5.5" x 8.5" postcard is exactly half a letter sheet. The 6" x 9" format is the largest common option and is roughly two-thirds the area of standard paper.

What size postcard should I use for direct mail marketing?

For budget-conscious, high-volume campaigns, use 4" x 6" to get the cheapest postage. For campaigns where you need more space for images, coupons, or detailed messaging, 5.5" x 8.5" or 6" x 9" gives you room to work with. The higher postage cost often pays for itself through better response rates.

Do I need to add bleed to my postcard file?

Yes. Add 0.125" bleed on all four sides. That means a 4" x 6" postcard file should be 4.25" x 6.25". Bleed prevents white edges from appearing after the card is trimmed. Keep important text and logos at least 0.125" inside the trim line too.

Can I mail an oversized postcard without an envelope?

Absolutely. Postcards up to 6" x 9" can be mailed without an envelope. They just won't qualify for the discounted postcard postage rate if they exceed 4.25" x 6". Larger postcards mail at the First-Class letter rate. Add a QR Code Generator link to your design so recipients can scan and respond instantly.

What paper thickness works best for postcards?

14pt cardstock is the industry standard for mailed postcards. It's durable enough to survive postal sorting without bending. For premium feel, 16pt matches the thickness of a credit card. 32pt ultra-thick stock turns a simple postcard into a keepsake-quality piece that people hold onto.