To work out that ratio, I started by taking six different varieties of dried beans—cannellini beans, red kidney beans, pinto beans, black beans, chickpeas, and black-eyed peas—and measured their volumes and weights both before and after cooking. (For more on how to cook dried beans, take a look at our step-by-step guide.) The good news is, while the conversions aren't perfectly consistent, they're close enough that we can come up with a handy rule of thumb: Most dried beans slightly more than double in both volume and weight once cooked.