Can Size Conversion Chart for Ingredients in Recipes

Decoding Older Recipes Listing Only the Name of the Can Size

Assorted tinned fruit & vegetables
Maximilian Stock Ltd. / Getty Images

You've been looking forward to making grandma's sauce recipe—it's an heirloom, passed down from generation to generation, one that your grandmother cooked and that you are committed to making a part of your family's favorite dishes. But some of the measurements aren't quite making sense—like what is a "no. 10 can"?

When it comes to modern recipe ingredient lists, we are familiar with the measurements of the ingredient listed, as well as the size of the can when applicable—for example: 1 can (15-ounce) tomato paste.

But older recipes may just list a can size—which is not a weight or volume measurement but just a name or number—and little else. This is particularly tricky if you're making grandma's traditional recipe for the first time and you aren't sure how much of an ingredient should be included. Or if you are downsizing a recipe meant to feed a crowd and have no idea how to cut a "no. 3 squat" can in half.

Luckily, there is a way to convert these old-fashioned can sizes into something more familiar. 

Can Size Conversion Chart

In the event you run across a recipe that doesn't have the measurements spelled out, consider some generally accepted conversions, both for how much to use and how much to buy of that canned ingredient.

 Can Size Name Weight Volume
 Picnic 10 1/2 to 12 ounces 1 1/4 cups
 12 ounces vacuum 12 ounces 1 1/2 cups
 No. 1 11 ounces 1 1/3 cup
 No. 1 tall 16 ounces 2 cups
 No. 1 square 16 ounces 2 cups
 No. 2 1 pound 4 ounces or 
 1 pint 2 fluid ounces
 2 1/2 cups
 No. 2 1/2 1 pound 13 ounces 3 1/2 cups
 No. 2-1/2 square 31 ounces scant 4 cups
 No. 3 51 ounces 5 3/4 cups
 No. 3 squat 23 ounces 2 3/4 cups
 No. 5 56 ounces 7 1/3 cups
 No. 10

 6 pounds 6 ounces to 7   pounds 5 ounces

 12 cups
 No. 300 14 to 16 ounces 1 3/4 cups
 No. 303 16 to 17 ounces 2 cups

Jar Size Conversion Chart

Jars used in preserving your own fruits and vegetables are considered "canned." If you are looking at an old canning recipe, it may list a jar size. These are a little less confusing than the can sizes as jars come in sizes that already reference volume and weight. While there may now be some fancy jars available, older recipes relied on good-old Mason jars.

 Jar Size Weight Volume
 Jelly Jar 4 ounces 1/2 cup
 Jelly Jar 8 ounces 1 cup
 Jelly Jar 12 ounces 1 1/2 cups
 Half Pint 8 ounces 1 cup
 Pint 16 ounces 2 cups
 Pint-and-a-Half 24 ounces 3 cups
 Pint-and-Three-Quarters 28 ounces 3 1/2 cups
 Quart 32 ounces 4 cups
 Half Gallon 64 ounces 8 cups
 Gallon 128 ounces 16 cups
 Storage Jar 14 ounces 1 3/4 cups
 Storage Jar 38 ounces 4 3/4 cups

Miscellaneous Size Conversions

We have all probably come across a recipe with odd or vague ingredient measurements—or maybe no measurements at all. Use some basic conversions to fill in the blanks.

 Ingredient Measurement Weight Volume
 Baby food jar 3 1/2 to 8 ounces depends on size
 Condensed milk 15 ounces 1 1/3 cups
 Evaporated milk 6 ounces 2/3 cup
 Evaporated milk 14 1/2 ounces 1 2/3 cups
 Frozen juice concentrate 6 ounces 3/4 cup

History of Can Sizes

To find out how many cups in a can are required, it's useful to have a little history of the canning industry. According to the guidebook Canning and How to Use Canned Foods, by the National Canners Association (it's now called the Food Products Association), while there are (or were) some can sizes considered standard, these measurements aren't based on any unit of volume or other requirements, and may lead to confusion for home cooks.

The Canners Association explained that in assigning the mysterious numbers to cans, the American can industry describes the dimensions of cylindrical cans by two numbers: diameter and height. The guide book's authors lamented the lack of foresight by the canning industry:

The regular No. 2 can is too large for peas, corn, and beans in amount for the average family to use at one time, and the unused part is not as attractive when reheated. The No. 3 can of tomatoes is likewise an anomaly though the objection is not so strong as for the No. 2. The No. 2½ can was introduced as a compromise on the No. 3, especially for fruits, but recently a better size is being used having the diameter of the No. 2½ but only half the height. After machines have once been built to make and close cans of a certain size, it is difficult to make changes no matter how desirable it may be.