Black Beans vs Kidney Beans

Bottom line

Per 100 g, Black Beans provides 118 kcal, 6.9 g protein, 19.8 g carbohydrate, 1.3 g fat and 6.7 g fiber; Kidney Beans provides 127 kcal, 7.8 g protein, 21 g carbohydrate, 1.3 g fat and 7 g fiber.

Kidney beans are slightly higher in protein, fiber and calcium; black beans a little higher in iron and magnesium. Both must be fully cooked — raw kidney beans contain a lectin that causes food poisoning.

In short: there is no nutritional reason to prefer one over the other — choose by taste, price and what the recipe needs.