A7 Envelope Size: Dimensions, Uses, and Mailing Guide (2026)

When you are ordering envelopes for invitations, greeting cards, or 5x7 photo prints, the A7 envelope is the size that almost always comes up first. Yet even people who have ordered it before sometimes confuse it with ISO A7 paper, get the dimensions slightly wrong, or are unsure whether the full invitation suite will need extra postage. This guide answers all of those questions using verified dimensions, current USPS rates, and a clear comparison of the A-size announcement series.

Whether you are planning a wedding mailing, a graduation announcement run, or a bulk greeting-card campaign, the details below will help you choose the right size, the right closure, and the right postage before you order anything.

Quick Summary

An A7 envelope measures 5-1/4 x 7-1/4 inches (133 x 184 mm) and is built to hold a standard 5x7 card. It is the most widely used invitation and announcement envelope in the United States. A single 5x7 card inside mails at the First-Class letter rate with one Forever stamp, though a full invitation suite that weighs more than one ounce requires additional postage.

• Exact size: 5-1/4 x 7-1/4 inches. The envelope is a quarter inch wider and a quarter inch taller than the 5x7 card it holds, giving about 1/8 inch of clearance on each side.
• Most common use is invitation and announcement mailing. Wedding invitations, graduation announcements, birthday invitations, baby showers, and holiday greeting cards all commonly use the A7 size.
• Postage starts at the First-Class letter rate. A single 5x7 card mails with one Forever stamp ($0.82 as of July 12, 2026). A full suite over one ounce costs more, and a non-machinable piece adds a surcharge.
• US A7 and ISO A7 are not the same size. The ISO A7 paper sheet is 74 x 105 mm, which is much smaller than the US announcement envelope called A7.
• A7.5 (5-1/2 x 7-1/2 inches) is available for bulkier suites. If your invitation suite has multiple inserts, a belly band, or a thick cardstock, A7.5 gives more room and reduces the risk of a tight or damaged seal.
• Wax seals and rigid embellishments require hand canceling. If you plan to use wax seals, ribbon, or charms, drop your assembled envelopes at the post office counter rather than running them through the automated sorter.

What are the exact dimensions of an A7 envelope?

The A7 envelope measures 5-1/4 inches wide by 7-1/4 inches tall (5.25 x 7.25 inches, or 133 x 184 mm). The envelope is designed with about 1/8 inch of clearance on each side around a standard 5x7 card, which is just enough room for the card to slide in smoothly without bunching at the edges.

The width-to-height ratio works out to approximately 1:1.38, which falls squarely in the USPS machinable range of 1.3 to 2.5. That means a single card in an A7 qualifies as a letter-size mailpiece and goes through automated sorting without a surcharge, as long as the assembled piece stays within the standard letter thickness and weight limits.

A7 envelope measurement summary

US A7 vs ISO A7: why do people get confused?

The confusion comes from overlapping naming conventions. In the ISO 216 paper standard used by most of the world, A7 refers to a paper sheet that is 74 x 105 mm (about 2.9 x 4.1 inches). That is roughly the size of a business card, and it has nothing to do with envelope sizing.

In the United States, A7 is part of the announcement-envelope series, which runs from A1 through A10. These are envelope sizes, not paper sizes, and the numbers correspond to the approximate card size each envelope was built to hold. The US A7 envelope at 5-1/4 x 7-1/4 inches is dramatically larger than the ISO A7 paper sheet.

If you are ordering from a US supplier, "A7 envelope" always means the 5-1/4 x 7-1/4 inch invitation-size envelope. If you are ordering paper stock or inserts and see "A7" referenced in an international context, verify the units and dimensions before assuming it matches the envelope.

What fits inside an A7 envelope?

The A7 envelope holds a 5x7 card or a 5x7 photo print. Because the clearance is only about 1/8 inch on each side, the insert should stay at or slightly under 5 x 7 inches to slide in cleanly without bending or dragging on the envelope edges.

For a standard single insert, such as one invitation card or one flat greeting card, the fit is comfortable. The problems start when you add multiple layers:

• A single 5x7 card: Fits perfectly. No issues with clearance, sealing, or postage at letter rate.
• An invitation card plus one insert (RSVP card or detail card): Usually still fits, though the combined thickness adds weight. Weigh before buying stamps.
• A full invitation suite with vellum overlay, belly band, RSVP card, return envelope, and detail card: The envelope may seal with difficulty or may bulge. A7.5 envelopes (5-1/2 x 7-1/2 inches) are the better choice for full suites.
• A 7x10 sheet folded once to 5x7: This fits, but the fold adds thickness. Check the assembled weight before ordering postage in bulk.
• Shaped or die-cut cards: Fine if the shape stays within the 5x7 footprint. Anything wider or taller will not slide in cleanly.

The practical rule is to assemble a complete sample, seal it, and weigh it before you finalize your postage order. A full invitation suite regularly exceeds one ounce, which moves it from a single-stamp letter to an additional-ounce rate.

What is an A7 envelope used for?

The A7 is the standard invitation and announcement envelope in the United States. It accounts for the majority of formal and semi-formal mailing volume in several categories:

Wedding invitations

The 5x7 invitation card is the default size for most wedding invitation suites. The A7 envelope pairs with it without any trimming or custom printing adjustments. The inner envelope, when used, is typically a plain A7 as well. For the outer mailing envelope, some couples choose a heavier-weight or colored stock, which is available in several wove and textured finishes.

Graduation announcements

Graduation announcements are almost universally printed on 5x7 cards and mailed in A7 envelopes. See the graduation announcements and invitations guide for a full breakdown of envelope sizing, postage, and ordering timelines for announcement mailings. Schools and universities ordering in quantity benefit from the no-minimum ordering available for blank stock.

Birthday and holiday invitations

Birthday parties, holiday parties, and seasonal event invitations frequently use 5x7 cards because printing vendors standardize on that size. The matching A7 envelope keeps the invitation rigid during mailing and gives recipients a clean presentation when they open the piece.

Greeting cards and holiday cards

Most commercially produced greeting cards are sized to fit an A7 or close to it. Holiday card mailings are one of the highest-volume uses of the A7 size during the fourth quarter of the year. See the greeting card envelope sizes guide for a comparison of A2, A6, A7, and A9 envelopes and the card sizes that go with each.

Baby shower and christening announcements

Baby announcements, shower invitations, and christening notices all commonly use 5x7 stock. The A7 envelope in a white or cream wove finish is the standard pairing for these events, though colored envelopes offer an option for more vibrant presentations.

Corporate and business mailings

Businesses use A7 envelopes for promotional postcards, customer appreciation cards, save-the-date mailers, and loyalty program communications. Custom printed envelopes with a return address and logo are available at businessenvelopes.com through the printed envelopes section, with production taking 7 to 10 business days.

How much postage does an A7 envelope need?

An A7 envelope with a single 5x7 card mails at the First-Class letter rate. As of the USPS rate adjustment effective July 12, 2026, the current rates are:

What makes an A7 mailing non-machinable?

Several common invitation additions push an A7 out of the machinable letter category and into the non-machinable surcharge:

• Wax seals on the flap or on a belly band
• Ribbons, charms, or raised embellishments
• Contents thicker than 1/4 inch
• Square envelopes (A7 is not square, but if you use a square envelope for any insert it carries a non-machinable charge)
• Envelopes with clasps or metal closures

If any of these apply to your mailing, take a fully assembled sample to your post office counter and ask for it to be hand-cancelled. Staff can verify the rate before you affix stamps to the whole run.

How does the A7 compare to other announcement sizes?

The A-size announcement series runs from A1 (the smallest) up through A10. The most commonly used sizes in the US for consumer and business invitation mailings are A2, A6, A7, and A9. Here is a direct comparison:

The A7 is the de facto standard because most invitation card printers and greeting card vendors have standardized on the 5x7 card size. If you are ordering cards and envelopes separately, confirming that your cards are exactly 5 x 7 inches (not 5.25 x 7.25) before ordering A7 envelopes will save you a return trip.

Should you use A7 or A9?

The A9 makes sense when your card is physically larger than 5 x 7 inches, when you have multiple large inserts, or when you want more visual presence in the mailbox. The A9 at 5-3/4 x 8-3/4 inches is noticeably bigger, which can work well for luxury invitations or oversized art prints. However, if your card is a standard 5x7, the A7 is the right match. Using an A9 for a 5x7 card will leave the card loose inside, increasing the chance of it sliding to one side and causing an uneven presentation.

What closure options are available for A7 envelopes?

The two main closure types for announcement-size envelopes are:

Gum flap (traditional moisture-activated)

A gum flap requires you to moisten the adhesive strip before pressing the flap down. Using a damp sponge rather than licking the flap directly is the recommended practice for large mailings, both for hygiene and for a more consistent seal. Gum flap envelopes are the standard for formal invitations where a clean, traditional finish is expected.

Peel and seal (self-seal)

Peel-and-seal envelopes have a protected adhesive strip under a paper or film liner. You peel the liner off and press the flap down without any moisture. This closure is faster for large-volume mailings, produces a more consistent seal, and is ideal when envelopes need to be assembled in batches rather than one at a time. See the full range of self-seal envelopes available at businessenvelopes.com.

Color options for A7 envelopes

Beyond white and cream, colored envelopes add visual impact to invitation mailings. A colored outer envelope can reinforce a theme or make the mailpiece stand out before the recipient even opens it. Common options include soft pastels for baby showers and spring events, deeper saturated colors for fall and winter mailings, and bright options for casual celebrations.

How do you address and print on an A7 envelope?

Addressing and printing on an A7 follow the same principles as any other envelope, with a few specific considerations for announcement-size pieces:

Addressing placement

The delivery address should be centered on the front of the envelope. For a 5-1/4 x 7-1/4 envelope, the address block typically starts around 2.5 inches from the top and 1.5 inches from the left edge, leaving enough room for the stamp in the upper right and the USPS barcode area at the bottom. The return address goes in the upper left corner.

Hand addressing vs printed labels vs digital printing

• Hand calligraphy: Most popular for formal weddings. Works on both white and colored envelopes if the ink has sufficient contrast. Dark or heavily colored envelopes may require white ink or a label.
• Printed labels: The fastest option for large volumes. Labels should be large enough to read clearly but positioned so they do not cross into the flap or the lower USPS barcode zone.
• Digital inkjet addressing: Fast and clean on white envelopes. Dark envelope stock can cause ink spread on inkjet printers, so test a few samples first or use white ink.

Custom return address printing

Custom-printed envelopes with your return address and logo are available through the printed envelopes section. Production for printed envelopes is 7 to 10 business days. Blank stock ships same or next business day, which gives you the option to print return addresses yourself if your timeline is tight.

Keep artwork away from the edges

If you are printing a design or pattern on the envelope itself, keep the artwork at least 1/4 inch from all edges, the flap fold line, and the glue seam. Printing too close to the seal area can interfere with the adhesive and cause the envelope to open in the mail.

What should you check before ordering A7 envelopes in bulk?

Ordering announcement envelopes in quantity is straightforward, but a few checks beforehand can save time and cost:

• Confirm your card dimensions: Measure an actual printed card, not just the file size. Printing tolerances can shift a 5x7 card to 5.1 x 7.1 or 4.9 x 6.9. If the card is consistently over 5x7, order A7.5 envelopes instead.
• Assemble and weigh a complete sample: Put a fully assembled and sealed sample on a postal scale before buying stamps. The first-class single-stamp threshold is one ounce. If your suite is close, weigh several samples because paper weights vary.
• Order 10 to 15 percent extra: Invitation and announcement mailings almost always have addressing mistakes, guests added after the initial list, and envelopes that are damaged or missealed. Ordering extra blanks upfront costs less than a second order later.
• Check if any embellishment makes the piece non-machinable: Wax seals, raised stickers, thick ribbon, and rigid inserts all trigger a $0.49 per-piece surcharge. Factor that into your total postage budget.
• Request hand canceling at the post office: For any non-machinable or fragile mailing, bring envelopes to the counter rather than dropping them in a street collection box. The automated sort can damage wax seals, ornate closures, or thick suites.

Browse the full range of envelope sizes and styles at all sizes envelopes to compare options before placing your order.

About the Author

This guide was researched and written by the Business Envelopes content team using USPS rate schedules effective July 12, 2026, and product specifications verified from the businessenvelopes.com catalog. A person reviewed the facts before publication. For questions about specific products or quantities, contact the Business Envelopes team at businessenvelopes.com.