Invitation envelope sizes
Use the A-series when you need the envelope to fit the card cleanly without looking swallowed or cramped.
The event and greeting-card default.
Often used for RSVP and enclosure cards.
That is where elegant sets go tight.
Quick check
How people usually get this wrong
They match the card size but ignore thickness, liners, and wrap. A card that slides into a bare envelope can feel much tighter once the full invitation suite is assembled.
- A7 is the familiar choice for 5 x 7 invitation cards.
- A2 works well for RSVP cards, short note sets, and announcement pieces.
- If the envelope is lined or the card stack is layered, leave more room than the flat dimensions suggest.
A-series invitation sizes (in / mm)
| Size name | Common name | Item size | Shape | Best use |
|---|---|---|---|---|
| A2 | Announcement envelope | 4.375 x 5.75 in (111 x 146 mm) | Envelope | RSVP cards and short notes |
| A6 | Announcement envelope | 4.75 x 6.5 in (121 x 165 mm) | Envelope | photos and invitations |
| A7 | Invitation envelope | 5.25 x 7.25 in (133 x 184 mm) | Envelope | 5 x 7 cards |
| A9 | Large invitation envelope | 5.75 x 8.75 in (146 x 222 mm) | Envelope | half-sheet cards and flat mailers |
Card stock, belly bands, and liners all change the real fit. Fancy pieces need a physical proof more than plain note cards do.
Common questions
What envelope fits a 5 x 7 invitation?
A7 is the usual fit. If the set includes thick stock, wrap, or extra layers, test the full stack before you commit.
Should RSVP cards use A2 envelopes?
That is a common pairing because A2 suits smaller insert cards well. It is still worth proving if the paper feels unusually thick.
Why do lined envelopes feel tighter?
Because the liner takes up real space and changes how the flap closes. The nominal size does not tell that part of the story.