Envelope Size Finder
Enter your flat card or insert size and we will point you to the standard envelope that fits with room to insert and seal.
Enter your flat card or insert size in inches.
A quick planning estimate — exact specs and pricing come with your quote. Request a free quote →
Envelope size FAQ
Need this done for you? We handle Print & Stationery for businesses across Buffalo and the Twin Cities.
A 5 x 7 inch card fits an A7 envelope (5.25 x 7.25 inches), the standard for invitations and announcements. The finder picks the right envelope for any insert size.
About a quarter inch larger in each direction so the card slides in and out easily and seals cleanly. The finder builds in that clearance.
Yes. We print invitations, announcements, and business mailers with coordinated envelopes, and can address and mail them too. See print & stationery and mailing services.
How to figure out what size envelope you need
The rule of thumb: your envelope should be at least a quarter inch bigger than the piece going inside it, in both width and height. That little bit of clearance is what lets a card slide in without catching, sit flat, and seal cleanly — any tighter and stuffing gets slow, any looser and the piece shifts around in the mail.
The finder runs that exact rule. It adds 0.25" to your insert’s width and height, then checks the result against the standard envelope lineup — A1, A2, A6, A7, and A9 announcement sizes, the 6" × 9" booklet, and 9" × 12" and 10" × 13" flats — and recommends the smallest envelope that clears both numbers. It even tries your piece rotated sideways in case that unlocks a smaller size. Anything bigger than a 10" × 13" flat calls for a custom envelope or flat mailer.
Worked example: a 5" × 7" invitation needs an envelope at least 5.25" × 7.25". A2 (4.375" × 5.75") and A6 (4.75" × 6.5") both come up short, so the finder lands on the A7 at exactly 5.25" × 7.25" — the standard invitation envelope. Want envelopes printed to match your cards? See print & stationery and mailing services.
Ready to start your project?
Tell us what you need and we'll put together a custom quote — no cost, no commitment.