We’ve put together the most complete information possible about recipe cards (including 400 free printable recipe cards) on a special section of our recipe card site. We added an info graphic about recipe card sizes too. I’m posting it here in case you haven’t seen it yet.
Here’s a snippet from the page, but you can read the full text here:
Recipe Card Sizes: There are generally 3 sizes of recipe cards to consider. The 3×5” card is the standard card for most of the last 100 years. (Our own 3×5 recipe cards can be found here.) The old recipe card boxes they fit into were designed for America’s small kitchens. As kitchens expanded, so did the capacity of recipe boxes and binders to allow for the now standard 4×6” recipe card. (Our 4×6 recipe cards are here.) The vast majority of all current recipe cards are this size. In the past decade a few brands have expanded to 5×7” recipe cards. (Ours are here.) You may want to avoid these, however, because while they may fit your own binder they may not fit a friend’s binder you wish to share with.
The reason 4×6 cards are about 77% of the cards we offer is because they are so much larger than 3×5 cards (a full 60% bigger) while being much more reasonable to handle than the enormous 5×7 recipe cards.
Ted and I have put in a lot of work on this new section of our site. I hope you enjoy it!