Canned beans instead of dried - how many cans should I use instead of 1lb dried?

Another way to think of it is to replace the food values of the dried beans with those of an equivalent amount of canned (cooked) beans.
Approximately 5 cans of 15 oz (or 5 cups) great northern beans replace the food values (calories, protein, carbohydrate) of 1 lb (2 cups) dried.

I found this conversion online and hope it helps.

A standard can of beans is 15 ounces. Small bags of beans you get at the store are usually 1 pound, but sometimes 2.

1 15-ounce can of beans equals
1/2 cup dry beans, before cooking
1 1/2 cups beans, after cooking