# Card Envelope Sizes and Guidelines

Are you planning on throwing a formal event anytime soon? Then you might want to consider mailing out your card invitations right away. However, before that, you should make sure that you get the right envelope size for your cards.

The size of a card envelope will depend on the size of the card itself. For instance, if you printed your invitation on A6 cards (105 × 148.5 millimeters or 4.1 × 5.8 inches), then you should use an A6 envelope, which will measure around 121 × 165 millimeters (4.75 × 6.5 inches).

As you can see, finding the right envelope size for your card isn’t that difficult. However, when different variables—e.g., folded cards, flat cards, type of envelopes, etc.—come into play, it can make finding the right envelope size a tad bit more confusing. Please continue reading to find all the information you need to know about card envelope sizes.

## Card Envelope Dimensions

Before you begin envelope shopping, you should have a pretty good idea of what kind of card you wish to send through the mail. After all, the purpose of the envelope is to house the card and not leave any portion of it sticking out. That means the envelope should enclose the entirety of the card, and the flap should fold over without any bulges or tears.

As long as you know what card size you use, finding the appropriate envelope size shouldn’t be that difficult. The following table will give you a good idea of an envelope’s measurements based on what size card it contains.

 Card and Envelope Size Envelope Dimensions (L × W in inches) A1 3-5/8 × 5-1/8 A2 4-3/8 × 5-3/4 A4 4-1/4 × 6-1/4 A6 4-3/4 × 6-1/2 A7 5-1/4 × 7-1/4 A8 5-1/2 × 8-1/8 A9 5-3/4 × 8-3/7 A10 6 × 9-1/2 #9 3-7/8 × 8-7/8 #10 4-1/8 × 9-1/2

It’s important to note that the dimensions listed above do not directly correspond with the size of the card. For instance, an A4 card measures 8-1/4 × 11-3/4 inches, whereas an A4 envelope is 4-1/4 × 6-1/4 inches. Due to the size of the card, you would most likely need to fold it or cut it into quarter-sections to fit inside the envelope perfectly. After all, hardly anyone sends invitations printed out on massive A4 cards.

## Envelope Types

If you go to your local office supplies store or a local invitation printer and ask for envelopes, the employee will most likely respond with a question of their own. “What type of envelope are you looking for?”

The next time you pay a visit to an office supplies store, try and see how many different types of envelopes they carry. Only then will you realize that finding the right envelope isn’t just a matter of finding the correct size.

Below, I’ll go over the different types of envelopes and categorize them by which ones are appropriate for sending cards.

### Envelopes for Cards

Square flap envelopes—this type of envelope has an elegant, square flap on the back. It is used to send invitations of all kinds and sizes, as well as greeting cards and photos.

Contour flap envelopes—this is similar to square flap envelopes except that it has a triangular flap in the back that nearly reaches the bottom of the envelope.

Square envelopes—these envelopes are equal in size on all sides, which is great for sending square cards and photographs.

Vertical-square flat envelopes—this is similar to the square envelope but is elongated on one side. It can house regular sheets of paper or rectangular cardstock.

Pointed flat envelopes—this is not unlike the contour flap envelope. The only difference is that the triangular flap extends to about the midway mark between the top and bottom sides of the envelope.

Lined envelopes—this is a standard square flap envelope, but the main difference is that it has a construction paper or metallic lining on the inside, which you can customize to make the invitation or card pop.

Mini envelopes—this type of envelope is much smaller than the other types of envelopes on this list. It is great for sending folded cards and business cards.

### Envelopes for Other Purposes

Regular envelopes—regular envelopes are mainly used to send tri-folded sheets of paper through the mail. It can technically be used to send cards, but it will leave too much empty space on the sides.

Window envelopes—this type of envelope has a transparent sheet of plastic that allows the receiver to catch a glimpse of the contents within. If you’ve received bills through the mail, this is the type of envelope your utility company uses.

Double-window envelopes—exactly like window envelopes, but they come with a secondary window.

Full-face window envelopes—exactly like window envelopes, but the transparent sheet extends to about an inch from all sides of the envelope.

Expansion envelopes—this type of envelope features an accordion-style flap, which helps it house thick documents like books or reports.

Open-end envelopes—this envelope style is longer than rectangular envelopes, but it has two flaps on the top and bottom that you can open.

Clasp envelopes—a clasp envelope comes with a metallic clasp and eyelet that is used to keep the flap shut.

Booklet envelopes—this type of envelope is mainly used to send formal documents through the mail.

Document envelopes—you would only use document envelopes to send thick reports, pamphlets, or magazines.

Specialty-use envelopes—do you remember receiving America Online discs in the mail? The company sent its discs using specialty envelopes.

## Will a 5 × 7 Envelope Fit a 5 × 7 Card?

One way you can find the perfect envelope for your card is by asking for an envelope size of the exact measurements of your card. For instance, if you want to send 5 × 7-inch cards, you should ask for a 5 × 7-inch envelope.

It’s worth mentioning that the dimensions of the envelope will not be exactly 5 × 7 inches. If it were, then it would be hard to insert and remove the card from the envelope.

BaronCooke

Baron Cooke has been writing and editing for 7 years. He grew up with an aptitude for geometry, statistics, and dimensions. He has a BA in construction management and also has studied civil infrastructure, engineering, and measurements. He is the head writer of measuringknowhow.com