Standard can sizes were developed years ago and refer to a complicated formula for computing the linear inches in the empty can - information that is infinitely more useful to you if you are a can manufacturer, but not too helpful in cooking.

Many old recipes referred to the can size needed because they contained a certain volume of food or an average net weight. Today, however, many food processors have shaved ounces as a way to maximize profits. A standard No. 303 can once contained 16 ounces. Now you'll find that same can size contains anywhere from 14.5 to 15.25 ounces.

Here are the standards for can-size equivalents for home use:

Can size - Volume in cups Picnic 1 1/4 No. 1 (11.5 ounces) 1 1/3 No. 300 (14 to 16 ounces) 1 3/4 No. 303 (16 to 17 ounces) 2 No. 2 (18 to 20 ounces) 2 1/2 No. 2 1/2 (29 ounces) 3 1/2 No. 3 (46 ounces) 5 3/4 No. 10 (6 pounds) 12