How much potassium does a banana carry?

December 27, 2025 •

4 min read

According to the USDA, a medium banana (about 7 to 8 inches long) contains around 422 mg of potassium. This well-known fruit is a convenient source of this vital mineral, though the exact amount can vary slightly depending on its size and ripeness.

Quick Summary

A medium-sized banana provides roughly 422 to 450 mg of potassium, a key electrolyte for heart health and muscle function. The amount varies based on the fruit's size, with larger bananas containing more of the mineral. Bananas are a good dietary source, but many other foods actually offer higher concentrations.

Key Points

Medium Bananas Provide 422-450mg of Potassium: A medium banana contains a significant amount of potassium, though the exact content varies by size.
Size Impacts Potassium Content: Larger bananas naturally have more potassium, with an extra-large one potentially offering over 500 mg.
Bananas Aren't the Highest Source: Despite their reputation, many other foods like baked potatoes, sweet potatoes, and spinach contain even more potassium per serving.
Potassium is Vital for Heart Health: The mineral helps regulate blood pressure and heartbeat, counteracting the effects of sodium.
Essential for Muscle and Nerve Function: Potassium is a crucial electrolyte that regulates muscle contractions and nerve signals throughout the body.
Part of a Balanced Diet: For a balanced intake, rely on a variety of potassium-rich foods, not just bananas.
Consult a Doctor for Medical Advice: For specific health concerns, particularly involving potassium, it is best to speak with a healthcare professional.

The Potassium Content of a Banana

For many, the image of a banana is synonymous with potassium. It's a convenient, portable, and sweet fruit that makes getting this essential mineral easy. But how much potassium does a banana carry, and how does it stack up against other dietary sources? The amount of potassium in a banana is primarily determined by its size. According to nutritional data from reputable sources, a medium banana (around 7 to 8 inches) typically provides between 422 and 450 mg of potassium.

Potassium Content by Banana Size

The amount of potassium scales with the size of the banana. The larger the fruit, the higher the potassium content. Here's a breakdown based on general size classifications:

Small banana (6-7 inches): Approximately 360 mg of potassium.
Medium banana (7-8 inches): Approximately 422-450 mg of potassium.
Large banana (8-9 inches): Over 480 mg of potassium.
Extra large banana (9 inches or longer): Can contain more than 500 mg of potassium.

It's important to note that a single banana, regardless of its size, does not contain enough potassium to meet the recommended daily intake for adults on its own. For adult men, the Adequate Intake (AI) is around 3,400 mg per day, while for adult women it is 2,600 mg. This means that a medium banana provides approximately 10-16% of the daily need for most adults.

Why is Potassium Important for Your Health?

Potassium is a crucial mineral and electrolyte that performs many vital functions within the body. Its roles extend far beyond just preventing muscle cramps. Here are some of the key health benefits associated with a diet rich in potassium:

Heart Health: Potassium helps regulate heartbeat and blood pressure. It counters the effects of excess dietary sodium, which can help lower blood pressure and reduce the risk of heart disease and stroke.
Fluid Balance: Working with sodium, potassium helps maintain the body's delicate fluid balance. Proper hydration and fluid levels are essential for optimal cell function and overall health.
Muscle Contractions: It is vital for normal muscle contractions, including the rhythmic beating of the heart. Low potassium levels can affect nerve signals and weaken muscle contractions.
Nervous System: Potassium is integral to the nervous system's ability to transmit nerve impulses, which facilitates communication between the brain and the rest of the body.
Kidney Health: This mineral helps regulate kidney function and the process of filtering waste from the blood.

Comparing Bananas to Other Potassium-Rich Foods

While famous for their potassium content, bananas are not the highest source. Many other foods offer a significantly larger dose of this mineral, making them excellent additions to a balanced diet.

Potassium Comparison: Bananas vs. Other Foods


Food Item	Serving Size	Approximate Potassium (mg)
Medium Banana	1 fruit	422-450 mg
Baked Potato	1 medium, with skin	926 mg
Sweet Potato	1 cup, cooked	572 mg
Spinach	1 cup, cooked	839 mg
Dried Apricots	1/2 cup	755 mg
White Beans	1/2 cup, cooked	502 mg
Plain Yogurt	1 cup	573 mg
Acorn Squash	1 cup, cooked	896 mg
Salmon	100 grams, cooked	380 mg

This table highlights that while bananas are a solid option, incorporating a variety of potassium sources can be more effective for meeting daily needs. Many vegetables, legumes, and even dairy products offer a higher concentration of this electrolyte.

Conclusion

So, how much potassium does a banana carry? On average, a medium banana provides a healthy dose of approximately 422 to 450 mg, contributing a useful percentage towards your daily requirement. However, it's crucial to understand that bananas are just one piece of the puzzle. A truly potassium-rich diet should be varied, including a wide array of fruits, vegetables, beans, and other foods. For those managing specific health conditions, such as kidney disease, potassium intake may need to be monitored. Consulting with a healthcare professional or registered dietitian is always the best approach to tailor dietary needs to your individual health status. For more information on dietary minerals, explore the NIH Office of Dietary Supplements website.

Potential Symptoms of Imbalanced Potassium Levels

Hyperkalemia (High Potassium)

Symptoms may include fatigue, muscle weakness, and numbness or tingling. Severe cases can lead to heart palpitations and irregular heartbeat, which requires immediate medical attention.

Hypokalemia (Low Potassium)

Symptoms can include muscle cramps, weakness, fatigue, and constipation. Persistent low levels can cause more serious issues, such as heart rhythm abnormalities.

Including Potassium-Rich Foods in Your Diet

Snack on dried fruits: Dried apricots, prunes, and raisins are concentrated sources of potassium.
Add legumes to meals: Lentils, white beans, and kidney beans can be added to soups, stews, and salads for a potassium boost.
Eat more root vegetables: Baked potatoes and sweet potatoes are among the richest sources of potassium.
Incorporate leafy greens: Cooked spinach and Swiss chard add significant potassium to your diet.
Choose diverse fruits: Cantaloupe, oranges, and avocados are great sources alongside bananas.

Frequently Asked Questions

A medium-sized banana, measuring approximately 7 to 8 inches, contains about 422 to 450 mg of potassium.

No, while bananas are a good source, many other foods contain higher amounts of potassium per serving. Examples include baked potatoes, spinach, dried apricots, and white beans.

A medium banana provides approximately 10-16% of the recommended daily potassium intake for an average adult, depending on gender.

It is difficult to consume a dangerous amount of potassium from bananas alone. Healthy kidneys are very efficient at flushing out excess potassium. However, individuals with kidney disease should consult a doctor about their intake.

Not getting enough potassium can lead to fatigue, muscle weakness, cramps, and in severe cases, abnormal heart rhythms.

Other foods high in potassium include sweet potatoes, spinach, white beans, yogurt, dried apricots, and salmon.

The potassium content does not change significantly with ripeness, but the form of its carbohydrates does. As a banana ripens, its resistant starch is converted into sugars.