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By Bliss & Bone
November 2026
The standard wedding invitation size is 5 x 7 inches (A7), mailed in a 5.25 x 7.25 inch A7 envelope. RSVP cards run smaller, at A2 (4.25 x 5.5) or 4-Bar (3.5 x 4.875), and save the dates come in A6 (4.5 x 6.25) or 5 x 7. Square invitations need extra postage.
The two charts below cover the main cards in a printed suite, drawn to scale, with envelope sizes and millimeter conversions. After them come the reasons 5 x 7 became the default and a guide to choosing a size that fits both your wording and your envelopes.
Each standard card size pairs with an envelope an eighth to a quarter inch larger, and the chart lists both.
| Shape | Size | Card | Envelope | Best for |
|---|---|---|---|---|
| A7LargeStandard | 5 × 7inches · 127 × 178 mm | 5.25 × 7.25 in | Wedding invitations, save the dates, inserts, menus | |
| A9Extra large | 5.5 × 8.5inches · 140 × 216 mm | 5.75 × 8.75 in | Oversized invitations, menus, programs | |
| 6.25 squareLarge square | 6.25 × 6.25inches · 159 × 159 mm | 6.5 × 6.5 in | Invitations, menus | |
| 5.5 squareSquare | 5.5 × 5.5inches · 140 × 140 mm | 5.75 × 5.75 in | Invitations, save the dates, menus | |
| A6Medium | 4.5 × 6.25inches · 114 × 159 mm | 4.75 × 6.5 in | Save the dates, inserts | |
| A2Small | 4.25 × 5.5inches · 108 × 140 mm | 4.375 × 5.75 in | RSVP cards, inserts | |
| 4-BarExtra small | 3.5 × 4.875inches · 89 × 124 mm | 3.625 × 5.125 in | RSVP cards, inserts |
Shapes drawn to scale. Rectangular sizes work in portrait or landscape. Square envelopes need extra postage.
Read the card column for what you design and print, and the envelope column for what you address and mail. Sizes are listed in inches because US printers and the Postal Service work in inches, with millimeters underneath for anyone comparing against international paper sizes.
Every rectangular size works in portrait or landscape. A 5 x 7 card turned on its side is still an A7 and still fits an A7 envelope. For liners and inner envelopes, see our full guide to wedding invitation envelopes.
Five by seven is the standard wedding invitation size for practical reasons. It mails as an ordinary letter in an A7 envelope that sits well inside USPS letter dimensions, and it holds a host line, both names, the date, the venue and a reception line at a readable type size. Nothing requires it, but it is the size every other card in a suite is planned around.
That balance is easy to underrate. Go larger and you trade the A7 envelope for an A9, which still mails as a letter but adds weight to every envelope once a reply card and details card go in. Go smaller and the wording starts to compete with the design. An A6 or A2 invitation suits a short, casual invitation, but a traditional host line naming both sets of parents will crowd it.
A9 earns its extra inch and a half when the invitation carries more text than a 5 x 7 can hold cleanly, such as a bilingual invitation or a host line that names both families in full. It also suits designs built around a large illustration that needs room to breathe.
Orientation is the other choice inside the standard size. The Mila Wedding Invitation is set as an A7 portrait, 5 x 7 inches standing tall. The Mila Wedding Invitation II turns the same design on its side as an A7 landscape, 7 x 5 inches, and the layout changes enough to read as a different invitation even though the card and envelope are identical. If you love a design but want it to feel less formal, try it in landscape before you change the size.
Most Bliss & Bone printed designs are set at 5 x 7, and the builder's size menu lists the other sizes each design supports. Custom sizes and shapes are available through your designer.
Each card in a printed suite steps down in size from the invitation, so the pieces stack neatly and travel together in one envelope. The chart below shows the size options for each piece, drawn to scale.
| Piece | Size options |
|---|---|
| Wedding invitation | A75 × 7 in127 × 178 mmStandardA95.5 × 8.5 in140 × 216 mm6.25 square6.25 × 6.25 in159 × 159 mm5.5 square5.5 × 5.5 in140 × 140 mm |
| Save the date | A64.5 × 6.25 in114 × 159 mmMost popularA75 × 7 in127 × 178 mm5.5 square5.5 × 5.5 in140 × 140 mm |
| RSVP cardReply card | A24.25 × 5.5 in108 × 140 mm4-Bar3.5 × 4.875 in89 × 124 mm |
| Details cardInserts and enclosures | A75 × 7 in127 × 178 mmA64.5 × 6.25 in114 × 159 mmA24.25 × 5.5 in108 × 140 mm4-Bar3.5 × 4.875 in89 × 124 mm |
| Menu | A95.5 × 8.5 in140 × 216 mmA75 × 7 in127 × 178 mm6.25 square6.25 × 6.25 in159 × 159 mm5.5 square5.5 × 5.5 in140 × 140 mm |
| Program | A95.5 × 8.5 in140 × 216 mm |
Shapes drawn to scale. Envelope sizes for each card are in the wedding invitation size chart above.
The standard RSVP card size is A2 (4.25 x 5.5 inches) or 4-Bar (3.5 x 4.875 inches). Both fit inside an A7 invitation envelope along with their own return envelope, and both return envelopes clear the Postal Service minimum of 3.5 x 5 inches for a letter, so the reply mails back as a standard letter.
Choose A2 when guests will write a note or a meal choice. Choose 4-Bar for a simple accept or decline line. Don't go smaller than 4-Bar for any card that travels by mail on its own, since anything under 3.5 x 5 inches falls below the Postal Service minimum.
Stamp and address every reply envelope before it goes into the suite, so guests only have to drop it in a mailbox. A single reply card in an A2 or 4-Bar envelope mails back on one Forever stamp.
If guests reply online, skip the reply card and its envelope entirely and print a small details card that points them to your RSVP page. For what to print on the card itself, see our wedding RSVP wording examples.
The standard save the date size is A6 (4.5 x 6.25 inches) or 5 x 7, the same size as the invitation. A6 suits a save the date because the card carries far less text than an invitation, and a slightly smaller card sets up the formal invitation that arrives later.
Postcard save the dates skip the envelope and mail on their own. The Postal Service caps postcard rates at 4.25 x 6 inches, so an A6 postcard at 4.5 x 6.25 is just over the limit and mails at the letter rate. If postcard pricing matters to you, size the card at 4.25 x 6 or smaller.
Browse printed wedding save the dates to see each size in context.
Details cards and other inserts sit between the invitation and the reply card in size. A6 (4.5 x 6.25) is the standard details card under a 5 x 7 invitation, and a full A7 details card works when it carries a map or a weekend schedule. Smaller inserts, such as accommodation or directions cards, use A2 or 4-Bar.
Leave a visible step between each layer. Cards that match the invitation exactly disappear behind it, and cards much smaller than the envelope slide around in transit. The order from back to front is invitation, details card, reply card and reply envelope, and the full stack has to fit the outer envelope together. For which inserts a suite needs in the first place, see what's included in a wedding invitation suite.
Menus and programs never go in the mail, so postage puts no limit on their size. Menus come in A9 and A7 as well as both square sizes, chosen to fit the place setting. Programs are usually A9 or a tall, narrow #10 card that is easy to hold through the ceremony.
Square wedding invitations come in two standard sizes: 5.5 x 5.5 inches in a 5.75-inch square envelope, and 6.25 x 6.25 inches in a 6.5-inch square envelope. Both cost more to mail than a rectangle of the same weight.
Square suits designs built on symmetry, such as a centered monogram or a wreath, and it reads as more modern than the familiar rectangle. Plan the inserts as rectangles. A 4-Bar reply card and its envelope fit inside the 5.75-inch square envelope, but an A2 reply envelope at 5.75 inches long does not. The 6.5-inch square envelope takes an A6 details card with room to spare.
The two squares also mail differently. The 5.75-inch square envelope stays a letter and pays the nonmachinable surcharge on top of the stamp, while the 6.5-inch envelope is taller than the Postal Service letter limit and mails at the higher large-envelope rate.
Wedding invitation size changes postage through shape and weight. A rectangular A-series envelope mails as a standard letter, and an assembled suite weighing one ounce or less needs a single Forever stamp. Square envelopes cost more to mail at any weight, and every ounce over the first adds postage.
The square penalty comes from a USPS rule about proportion. To go through the sorting machines, a letter's length divided by its height has to fall between 1.3 and 2.5. A square envelope scores 1.0, so it is sorted by hand and pays the nonmachinable surcharge on top of the stamp. For comparison, an A7 envelope scores about 1.38 and an A2 envelope about 1.31, both inside the rule.
Height sets the other limit. The Postal Service treats any envelope taller than 6.125 inches as a large envelope rather than a letter, which is why the 6.5-inch square envelope that holds a 6.25 square invitation mails at the large-envelope rate. Every rectangular size on the chart stays under that line.
Shape is one trigger among several. A wax seal that makes the envelope uneven, a rigid enclosure such as an acrylic card, or a string or button closure will each push a letter into the nonmachinable category.
Weight is the easier one to miss. A suite that feels light can still pass one ounce once a reply card, its envelope, a details card and a liner are inside. Assemble one complete suite with every piece and the outer envelope, have it weighed at the post office, and buy stamps for that weight.
A standard size keeps the envelope and the postage on their simplest path, and stepping outside the chart can add cost to either one of them.
A custom size needs envelopes cut to fit, and a square invitation adds postage to every envelope you mail. Each extra insert adds printing and weight as well.
Print method changes the total too. Letterpress wedding invitations press the design into thick cotton paper, and letterpress and foil suites start at a higher price than flat-printed ones. Our printed wedding invitations builder prices each size and finish as you choose it, so you can compare sizes on any design that offers more than one before you order.
Order five to ten extra invitations beyond your guest count for keepsakes and late additions to the list. For a full breakdown of what a suite costs, see how much wedding invitations cost.
US invitation sizes and international paper sizes share letter names but not dimensions, which catches couples who order from a printer abroad or design on a template built for A4 paper. A US A6 card is 4.5 x 6.25 inches (114 x 159 mm). An ISO A6 sheet, the size used across the UK and Europe, is 105 x 148 mm, about 4.1 x 5.8 inches, and it sits loose in a US A6 envelope.
The gap matters more one size up. An ISO A5 card is 148 x 210 mm, or about 5.8 x 8.3 inches, which is wider than the 5.75-inch US A9 envelope and will not fit inside it. If any part of your suite is printed outside the US, match card to envelope in millimeters using the conversions in the wedding invitation size chart.
Start with the envelope and the wording, then let the design decide the rest.
Choose the card and envelope together. Fall for a square design and you have also chosen square envelopes and square postage. Price both before you commit to the card.
Fit the wording before the design. Write out your full invitation text first. If the host line, names, date, venue and reception line won't sit on a 5 x 7 at a comfortable size, move up to A9 rather than shrinking the type. Our wedding invitation wording examples show how much text a formal invitation carries.
Keep the type readable. A small card forces small type, and script fonts lose legibility first. Print a test page at actual size and read it at arm's length before you approve a proof.
Build the suite as a hierarchy. The invitation is largest, the details card comes next and the reply card is smallest. Matching sizes make the suite harder to assemble and harder to read in the hand.
Treat bigger as a choice, not an upgrade. An oversized invitation adds weight to every envelope and is harder for guests to prop on a shelf. Save A9 for invitations that need the space.
A digital wedding invitation has no paper size and no postage, so the decisions that shape a printed suite drop away. Digital invitation dimensions come down to how the design reads on a phone screen, where a portrait layout fills the display and a landscape one shrinks to fit. Bliss & Bone online invitations are designed in the same proportions as a 5 x 7 printed card.
Our online wedding invitations send by email with RSVP tracking built in, so there is no reply card or return envelope to size at all.
The most common wedding invitation size is A7, or 5 x 7 inches, the industry standard. It's the easiest size to find envelopes for and the most budget-friendly to print. And standard size doesn't mean boring: fonts, colors, paper, and design elements can still make yours completely one of a kind.
Yes. A standard A7 fits within one stamp, but square or oversized invitations, or suites with RSVP cards and inserts, will likely need extra postage. Square envelopes in particular don't fit through USPS machines easily. Weigh a complete sample suite before you order stamps.
A6 (4.5 x 6.25 inches) is the standard Save the Date size, though A7 works if you want consistency across your suite. Save the Dates are typically more minimal, and a slightly smaller card creates a natural sense of progression when your formal invitations arrive later.
Yes. A7 is the standard, but custom sizes and shapes are available. Want an oversized A9 for more drama, or a compact 4-Bar for something minimal? Just know that custom sizes need envelopes cut to fit, and square sizes cost more to mail.
Smaller sizes like A6 or A2 work well for casual aesthetics and keep a suite light. The tradeoff is space, with less room for details or design. If you're going smaller, plan on insert cards to carry the overflow.
No, and they shouldn't be. The standard hierarchy: main invitation largest (A7 or A9), inserts mid-size, reply cards smallest (A2 or 4-Bar). This layering looks intentional and makes envelope stuffing easier. Just confirm your sizes work together before you order.
A 5 x 7 invitation goes in an A7 envelope, which measures 5.25 x 7.25 inches. The extra quarter inch on each side leaves room for a details card and a reply card with its envelope tucked in front of the invitation. An A7 envelope mails as a standard letter as long as the full suite weighs one ounce or less.
RSVP cards are A2 (4.25 x 5.5 inches) or 4-Bar (3.5 x 4.875 inches), returned in a 4.375 x 5.75 or 3.625 x 5.125 inch envelope. Both fit inside an A7 invitation envelope. A2 leaves room for meal choices or a note, and 4-Bar suits a simple accept or decline line.
An A9 envelope measures 5.75 x 8.75 inches and holds a 5.5 x 8.5 inch card. That is half a sheet of standard letter paper, so A9 is the size to choose when an invitation or menu needs more room than a 5 x 7 allows.
Ready to choose a size? Order wedding paper samples to feel the stocks in person before you commit, then pick a design and set its size in the builder.