The most common save the date size is 5" x 7", followed closely by the 4" x 6" postcard. These formats balance design flexibility with mailing convenience and are widely supported by print shops and template tools.
Other options - like square cards, magnets, or mini sizes - can help your save the date stand out, but they often come with trade-offs: higher postage, non-standard envelopes, or less layout space.
If you're designing your own, size impacts everything from photo clarity to mailing costs - so it's worth getting right from the start.
Save the Date Sizes Compared - So You Can Pick the Right One the First Time
From classic flat cards to budget-friendly postcards and stylish magnets, this chart helps you compare the most popular save the date sizes at a glance. You’ll see how each option fits with envelopes, postage costs, and design flexibility - so you can choose confidently and avoid mailing surprises later.
|
Format |
Dimensions |
Envelope Size |
Postage Notes |
Best For |
|
Flat Card |
5" x 7" |
A7 |
$0.68 (First-Class) |
Versatile, matches invite suite |
|
Postcard |
4" x 6" |
Optional |
$0.53 (Postcard Rate) |
Budget-friendly, simple designs |
|
Magnet |
4" x 6" (or) |
A6 or A7 |
~$1.08 (w/ surcharge) |
Fridge keepsake, photo-heavy |
|
Square Card |
5" x 5" |
Square |
~$1.08 (w/ surcharge) |
Unique, modern aesthetic |
|
Mini Card |
3.5" x 5" |
A1 (4Bar) |
$0.68 (First-Class) |
Minimalist or intimate weddings |
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Visual Size Guide: Preview Card Dimensions at Home
Not sure how big a 5" x 7" or 3.5" x 5" card really feels in your hand? Download our printablesave the date size guide to see the most common save the date formats overlaid to scale on a standard sheet of paper.
Print it at 100% (no scaling) and compare flat cards, postcards, magnets, and square formats side-by-side. It’s the easiest way to decide what feels right for your design - before you order.
Includes:
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5" x 7" Flat Card
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4" x 6" Postcard or Magnet
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5" x 5" Square Card
-
3.5" x 5" Mini Card
🔗 [Download the Printable PDF]
Just print and cut - or hold your photos or layouts up to the outlines to test the fit.
5" x 7" Save the Date (Most Popular)
Source: JunePaperStudio
The most popular save the date format - and for good reason. A 5” x 7” flat card offers plenty of room for a photo and key wedding details without looking crowded. It’s also the standard size used for formal invitations, making it a natural choice for coordinating your entire suite.
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Postage: Mails with a standard first-class stamp (no surcharge).
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Envelope: Pairs with an A7 envelope - widely available and easy to match.
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Format Notes: Offers the most layout flexibility. Great for designs with images, text, and spacing. Can be printed vertically or horizontally.
Pro Tip: Choosing 5” x 7” now makes it easier to keep your full stationery set visually consistent - most invitation and RSVP templates are designed around this size.
4" x 6" Save the Date (Postcard)
Source: namiprintstudio
A popular pick for budget-conscious couples, the 4" x 6" postcard is small, simple, and mail-ready without an envelope. At 4" x 6", it’s the minimum size that qualifies for USPS postcard-rate postage - but still offers enough space for a photo and the essentials - names, date, and maybe a website.
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Postage: Eligible for USPS postcard-rate stamp (cheaper than a standard stamp).
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Envelope: Optional - can be mailed bare or sleeved.
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Format Notes: Limited layout space. Best for simple, horizontal designs. Not ideal for detailed timelines or long messages.
Pro Tip: 4" x 6" is the smallest size you can mail as a postcard - any smaller won't qualify for USPS postcard rates and may be rejected. Always double-check your printer or template tool to ensure the final trim size meets this exact minimum.
Save the Date Magnets (4" x 6" or 5" x 7")
Magnets are a practical keepsake that guests actually hang up - but they come with mailing trade-offs. Most couples choose either 4" x 6" or 5" x 7", depending on how much photo or text space they want. Both sizes fit standard envelopes, but their thickness can trigger extra postage costs.
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Postage: Typically requires a non-machinable surcharge due to weight or rigidity.
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Envelope: A6 for 4" x 6", A7 for 5" x 7" - an envelope is required to avoid damage.
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Format Notes: Heavier than cardstock. Designs should be simple and bold, as magnet printing lacks fine detail resolution.
Pro Tip: Even standard-sized magnets usually count as “non-machinable” and cost more to mail. According to USPS guidelines, expect to pay around $1.08 per card (standard stamp + surcharge). Always test-mail one to confirm postage before sending in bulk.
Square Save the Dates (e.g. 5" x 5")
Square cards make a bold visual statement, but they break from USPS standard dimensions which means higher mailing costs. The 5" x 5" format is the most common, offering a balanced, modern look while still fitting a square envelope.
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Postage: Requires a non-machinable surcharge, even if weight is under 1 oz.
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Envelope: Requires a square envelope (typically 5.25” x 5.25”) - not always included in basic print packages.
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Format Notes: Symmetrical layout space works well for centered designs. Square cards stand out visually but are more expensive to mail in volume.
Pro Tip: USPS treats all square mail as non-machinable, regardless of size or weight. As of 2025, that means a single square save the date typically costs $1.08 to mail. Always test-mail one to verify the final cost with your envelope.
Mini Save the Dates (e.g. 3.5" x 5")
Source: JuneStudioDesigns
The smallest size that still mails reliably, mini save the dates are ideal for minimalist designs, intimate weddings, or elopements. At 3.5" x 5", they fit just the basics - and not much more.
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Postage: Mails with a standard first-class stamp (no surcharge, as long as it's machinable).
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Envelope: Pairs with a 4Bar (A1) envelope - check if your printer or supplier includes these, as they’re less common than A7.
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Format Notes: Limited space for both visuals and text. Works best when you strip down to name, date, and a short URL.
Pro Tip: 3.5" x 5" is the minimum size for USPS to accept as a letter. Anything smaller may be rejected or returned. Always confirm your final trim size meets or exceeds the minimum mailing dimensions: 3.5" high × 5" wide.
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What Size Save the Date Should You Choose?
Still weighing your options? Here's how the most popular save the date sizes stack up:
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5" x 7" – The go-to for a reason. Spacious, elegant, and matches most invitation suites.
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4" x 6" – Budget-friendly and easy to mail. Great for simple designs or large guest lists.
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Magnets – Fridge-worthy and memorable, but bulkier and pricier to send.
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Square / Mini – Stylish and unique, but less forgiving in terms of layout and postage.
Every size has its trade-offs. Think about how you want your save the date to feel - and how much you're mailing. A quick test print can save you from surprises later.
