Standard card sizes: what do all those letters mean?

Uncode the codes of card blanks to know what sizes come as standard for your card making

a5 size
a5 size

Like paper, there are standard sizes of card available to buy, all with strange codes with hidden meanings.


The names for card codes can be confusing, because a card is folded in half. Rather than reflecting the size of an unfolded piece of card, the sizes and measurements reflect the size of the folded card – or the front face. For example, an A5 card when unfolded will be A4 paper size. Folding it in half pushes it up a number, so an A4 sheet of card will make an A5 card when folded in half.

As with paper sizes, the smaller the number is, the bigger the card blank will be.

Whether you are going to buy card blanks to decorate yourself, or make your own cards, it is good to know the common sizes of card available.

Crafting to the standard sizes will mean it is much easier to buy envelopes for your cards, and can make it cheaper to post your cards in some countries.

What size is a5 card?

This is a sheet of a4 card folded in half

  • 14.8 x 21cm
  • 5.8 x 8.3in

What size is a6 card?

This is a sheet of a5 card folded in half

  • 10.5  x 14.8cm
  • 4.1 x 5.8in

What size is a7 card?

This is a sheet of a6 card folded in half

  • 4.4 x 10.5cm
  • 2.9 x 4.1in

What size is DL card?

DL cards are longer and thinner than other card sizes and are a third of a sheet of a4

  • 21 x 9.9cm
  • 8.3 x 3.7 in

Envelope sizes

Envelope sizes are designed to work with card blanks with the same number.

A c5 envelope is designed to fit an a5 card – it will be slightly larger than the card so the card can fit inside the envelope.

standard card sizes envelope

Make your own envelopes

It’s easy to make your own envelopes using our free templates. You can make them super decorative or simply crated – the choice is yours. Find the free envelope template


Want to make more of envelopes in your craft project? Take a look at our glorious free vintage letter and typewriter patterned papers for more inspiration and free printable artwork.