A recipe calls for a can (15oz) of cooked beans. How many cups or oz's is that to dry beans? Is this conversion even possible to estimate given that beans differ in amount of water absorption?
According to the Kitchen Companion, a terrific general handbook which I recommend, 1 lb (about 2 cups) of dried beans is roughly 6 to 7 cups cooked beans, and one 15oz can of cooked beans is roughly 1.75 cups drained, making it equivalent to 1/4 to 1/3 lbs ( or 1/2 to 3/4 cup) dried.
Per my personal experience, dried beans increase in volume from 2.5X at the low end (red lentils, mung beans, etc.) to 5X at the high end (garbanzos). 3X or 3.5X is a good median value for this.
So what kind of beans are we talking about?