A cup of cooked beans delivers roughly 3.6 to 5.2 mg of iron, depending on the variety. That’s a meaningful chunk of the daily requirement for most adults, and it makes beans one of the most accessible plant-based iron sources available.
Iron Content by Bean Variety
Not all beans are created equal when it comes to iron. The numbers below are based on a half-cup cooked serving, which is the standard portion size used in nutrition references. Double them for a full cup.
- Kidney beans: 2.6 mg per half cup (5.2 mg per cup)
- Chickpeas (garbanzo beans): 2.5 mg per half cup (5.0 mg per cup)
- Lima or navy beans: 2.3 mg per half cup (4.6 mg per cup)
- Black, pinto, or great northern beans: 1.8 mg per half cup (3.6 mg per cup)
Canned beans tend to come in a bit lower. Canned kidney or garbanzo beans provide about 1.6 mg per half cup, likely because some minerals leach into the canning liquid. Draining and rinsing the beans, which most people do, removes that liquid entirely.
How That Stacks Up Against Daily Needs
Adult men and anyone over 51 need about 8 mg of iron per day. Women between 19 and 50 need 18 mg, more than double, largely because of menstrual losses. A single cup of kidney beans covers about 65% of the daily target for men and roughly 29% for premenopausal women.
There’s an important caveat for vegetarians and vegans. The National Institutes of Health recommends that people who don’t eat meat, poultry, or seafood aim for nearly twice the standard amount of iron. That means roughly 16 mg per day for men and 36 mg for younger women. The reason comes down to absorption, which is the real story with beans and iron.
Why Your Body Absorbs Less Iron From Beans
Iron in food comes in two forms. Animal foods contain heme iron, which your body absorbs efficiently. Beans contain non-heme iron, and your body is far pickier about absorbing it. Research published in The American Journal of Clinical Nutrition found that women absorbed only about 2% of the iron from bean meals when eaten without vitamin C. That’s a dramatic gap compared to heme iron, which is typically absorbed at rates of 15 to 35%.
Beans also contain compounds called phytates and polyphenols that bind to iron in the digestive tract, making it harder for your intestines to pull the mineral into your bloodstream. This doesn’t mean beans are a poor iron source. It means you need to be strategic about how you eat them.
How to Get More Iron Out of Your Beans
The simplest trick is pairing beans with vitamin C. Adding tomatoes to a chili, squeezing lemon over hummus, or eating a side of bell peppers with a bean dish can significantly boost absorption. Vitamin C converts non-heme iron into a form your gut can grab more easily.
How you prepare beans before cooking also matters. Research on legumes has shown that sprouting beans for about 48 hours before cooking increases the proportion of absorbable iron from roughly 16% to 21% of total iron content. Soaking and then pressure cooking, or removing the outer hull before cooking, reduces the phytates and polyphenols that block absorption. In one study, dehulled and soaked beans that were then pressure cooked had the lowest levels of these absorption-blocking compounds, and iron bioavailability nearly doubled compared to raw, unprocessed beans.
On the flip side, drinking coffee or tea with a bean-heavy meal can reduce absorption further, since the tannins in those beverages also bind to non-heme iron.
Beans vs. Beef for Iron
A common question is whether beans can truly replace meat as an iron source. Calorie for calorie, they actually come out ahead. In a 200-calorie serving, cooked black beans provide about 3.2 mg of iron, while the same calorie amount of grass-fed ground beef delivers 1.7 mg. That’s nearly twice as much iron per calorie from the beans.
The catch, again, is absorption. Because beef contains heme iron, your body may extract more usable iron from that smaller number. Still, for people eating beans regularly alongside vitamin C-rich foods, the total contribution adds up. A clinical feeding trial in Rwanda found that women who ate iron-rich beans daily for 128 days measurably improved their iron status. The same trial also linked the higher iron levels to better physical work capacity and improved cognitive performance, showing that bean-sourced iron, consumed consistently, does translate into real physiological benefits.
Practical Amounts for Meeting Your Needs
If beans are a cornerstone of your diet rather than just an occasional side, the math works in your favor. Two cups of cooked kidney beans per day would provide about 10.4 mg of iron before accounting for absorption. Spread across meals and paired with absorption boosters like citrus, tomatoes, or peppers, that’s a solid foundation. Most people eating a varied plant-based diet combine beans with other iron sources like fortified cereals, lentils, tofu, and dark leafy greens to reach their target comfortably.
For people who eat both plants and meat, even a half cup of beans at lunch adds a reliable 1.8 to 2.6 mg to the daily total, often enough to close the gap between what a typical diet provides and what the body actually needs.