How much potassium is in black beans?
Black beans has 305 mg of potassium per 1/2 cup cooked (86 g) — about 6% of the 4,700 mg Daily Value. That's 355 mg per 100 g, roughly 0.7× a medium banana (~422 mg).
USDA FoodData Central · cooked, boiled · FDC 173735
Potassium by portion
| Portion | Potassium | % DV | Sodium | Calories |
|---|---|---|---|---|
| 1/2 cup cooked (86 g) | 305 mg | 6% | 1 mg | 114 |
| 100 g | 355 mg | 8% | 1 mg | 132 |
| 1 oz (28 g) | 101 mg | 2% | 0 mg | 37 |
% DV against the FDA Daily Value of 4,700 mg of potassium. Whole foods are naturally potassium-rich and low in sodium — the ratio heart guidelines (like DASH) favor. Values from USDA per-100 g data (FDC 173735, SR Legacy). cooked, boiled.
Black beans are a quietly reliable potassium source: a 1/2-cup serving of cooked beans (86 g) delivers about 305 mg of potassium, which is roughly 6% of the 4,700 mg Daily Value and about 0.7× the potassium in a medium banana (~422 mg) — about two-thirds of a banana from a standard side. Per 100 g that’s 355 mg, and a full cooked cup (about 172 g) reaches roughly 611 mg, nearly a banana and a half. As with most legumes, the potassium arrives bundled with fiber and protein rather than the sugar you’d get from fruit.
Why the potassium matters — and the low-sodium catch
Potassium is the mineral that works against sodium to support healthy blood pressure: it helps blood vessels relax and helps your kidneys excrete excess sodium, which is why the blood-pressure-lowering DASH pattern is built on potassium-rich, low-sodium foods. Black beans fit that mold when you start from dry — cooked without salt, they hold only about 1 mg of sodium per serving, so a half cup gives you ~305 mg of potassium against essentially no sodium. The one thing that breaks the ratio is the can: canned black beans can carry several hundred milligrams of added sodium per serving. Rinse canned beans well (a quick drain-and-rinse washes off a good chunk of the surface salt) or reach for a no-salt-added can if blood pressure is your concern. (General nutrition information, not medical advice — people with kidney disease are often told to limit potassium and should follow their clinician’s guidance.)
Potassium with a wall of fiber
The reason black beans beat fruit as a potassium source for many people is everything stacked next to the mineral. The same 1/2-cup serving brings about 7.5 g of fiber — a quarter or more of a day’s worth — plus roughly 7.7 g of plant protein, all for around 114 calories. That’s potassium, fiber, and protein in one naturally low-sodium scoop, a combination a banana can’t match. Folded into a burrito bowl, a soup, or a salad, a cup of black beans quietly adds 600-plus milligrams toward a potassium target most people miss, while the fiber slows digestion and keeps you full.
For the protein side of black beans — including how rice and beans form a complete protein — see protein in black beans.
Frequently Asked Questions
How much potassium is in a serving of black beans?
About 305 mg of potassium in a 1/2-cup serving of cooked black beans (86 g), which is 355 mg per 100 g (USDA FDC 173735). A full cooked cup (about 172 g) brings roughly 611 mg — and beans cooked from dry carry almost no sodium, around 1 mg per serving.
What percent of the daily value for potassium is that?
Roughly 6% of the 4,700 mg Daily Value per 1/2 cup, and about 13% for a full cup. Since most people fall short of 4,700 mg a day, a bean side delivering 6% — alongside a big dose of fiber — is a solid, low-effort contribution.
How does black bean potassium compare to a banana?
A 1/2 cup is about 0.7× a medium banana (~422 mg), so roughly two-thirds of a banana from a standard side, and a full cup clears nearly one and a half bananas. Black beans add fiber and protein the banana lacks, which is why they're a worthwhile potassium source beyond fruit.
Why does potassium matter?
Potassium balances sodium in the body and supports healthy blood pressure by helping blood vessels relax and helping the body clear excess sodium — the principle behind heart-focused eating patterns like DASH, which lean on potassium-rich, low-sodium foods such as beans. It also supports normal muscle and nerve function. This is general nutrition information, not medical advice.
Do canned black beans have more sodium than dried?
Yes. Black beans cooked from dry are extremely low in sodium — about 1 mg per serving — so the potassium-to-sodium ratio is excellent. Canned black beans can carry a few hundred milligrams of added sodium per serving; draining and rinsing them cuts a good share of it, or choose a no-salt-added can.
When was this data last verified?
2026-06-04, against USDA FoodData Central FDC 173735 (Beans, black, mature seeds, cooked, boiled, without salt; SR Legacy). We re-verify reference pages periodically and update when USDA revises the entry.
Whole-food values are USDA reference data, not a Labelgrade (that score is for branded packaged products). High-potassium diets aren't for everyone — people with kidney disease are often told to limit it; this is reference data, not medical advice. See our methodology.