How Many Calories in a Banana? Sizes & Nutrition Facts

Few snacks are as ubiquitous as the banana—tucked into lunchboxes, blended into smoothies, or eaten straight from the peel. One medium banana contains roughly 105 calories according to the USDA, making it a modest snack that sits comfortably within most daily eating plans.

Medium banana (7-8 inches): 105 calories ·
Small banana (6-7 inches): 90 calories ·
Carbs per medium: 25-27 grams ·
Calories per 100g: 89 calories

The following table summarizes verified nutrition data for a medium banana, drawing from tier-1 government and academic sources.

How many calories are in 1 average banana?

A medium banana (7-8 inches, 118 grams) delivers approximately 105 calories according to USDA data. That number shifts noticeably depending on the banana’s size: an extra small banana under 6 inches weighs just 81 grams and carries 72 calories, while a large banana at 8-9 inches tips the scale at 136 grams with 121 calories. The extra large varieties—those stretching 9 inches or longer at 152 grams—hit 135 calories.

For context, the Dietary Guidelines for Americans suggest carbohydrates should make up 45–65% of total daily calories. A single medium banana represents roughly 5% of a standard 2,000-calorie diet. That leaves plenty of room for the rest of your meals.

Calories by banana size

Healthline nutrition database breaks banana calorie counts into five practical tiers:

• Extra small (under 6 inches, 81g): 72 calories
• Small (6-7 inches, 101g): 90 calories
• Medium (7-8 inches, 118g): 105 calories
• Large (8-9 inches, 136g): 121 calories
• Extra large (9+ inches, 152g): 135 calories

If you’re counting sliced or mashed banana, portions grow quickly. One cup of sliced banana (150g) reaches 134 calories, while a cup of mashed banana (225g) climbs to 200 calories. That difference matters if you’re baking or making smoothies.

Ripe vs unripe banana calories

The calorie count doesn’t change dramatically as a banana ripens, but its composition does. Unripe green bananas are composed of up to 80% starch, according to Ethical Nutrition. As the fruit ripens, enzymes convert that starch into sugar. By the time a banana reaches full yellow ripeness, starch content drops to below 1%.

This starch-to-sugar conversion means riper bananas taste sweeter and contain more straightforward carbohydrates your body can absorb quickly. Less ripe bananas offer more resistant starch—a type that behaves more like fiber and passes through your digestive system less digested.

Is 1 banana a day too much sugar?

One medium banana contains about 14 grams of naturally occurring sugar, according to USDA data. Harvard T.H. Chan School of Public Health cites a slightly higher figure of 15 grams for a medium ripe banana. These numbers sound substantial, but context matters: the American Heart Association recommends limiting added sugars to no more than 25 grams daily for women and 36 grams for men—and a banana’s sugar comes wrapped in fiber, which slows absorption and moderates blood sugar spikes.

A medium banana delivers 3 grams of dietary fiber, which helps your body process its natural sugars more gradually. The fiber acts as a buffer, preventing the sharp blood sugar spikes associated with candy, soda, or other high-glycemic foods.

Sugar content in bananas

The sugar in bananas is entirely natural— fructose, glucose, and sucrose in roughly equal portions. Because the fruit contains no added sugars and comes with fiber, vitamins, and minerals, most nutrition experts consider bananas a wholesome choice even for people monitoring sugar intake. The Harvard T.H. Chan School of Public Health Nutrition Source notes that a medium ripe banana provides “about 110 calories, 0 gram fat, 1 gram protein, 28 grams carbohydrate, 15 grams sugar (naturally occurring), 3 grams fiber, and 450 mg potassium”—framing it as a nutrient-dense food rather than a sugar problem.

Daily sugar limits

The World Health Organization suggests that free sugars should constitute less than 10% of total daily energy intake, with a further reduction to below 5% for additional health benefits. A single medium banana containing roughly 14–15 grams of sugar fits comfortably within those guidelines for most adults.

For people with diabetes or insulin resistance, pairing a banana with protein or healthy fat (such as peanut butter or cheese) can further blunt any glycemic response.

Are bananas good for dieting?

Bananas can support weight management, but their effectiveness depends on how and when you eat them. The fruit provides quick energy from carbohydrates, satisfies sweet cravings without processed sugars, and delivers 3 grams of fiber per medium banana to help you feel fuller longer. A medium banana also offers 450 mg potassium—an essential mineral that supports muscle function during exercise and helps balance fluid levels.

According to Healthline nutrition database, “bananas are tasty and nutritious. They make an excellent, healthy, and low calorie snack.” The publication notes that roughly 93% of a banana’s calories come from carbs, 4% from protein, and 3% from fat—a macronutrient profile that makes bananas an efficient energy source rather than a protein-dense food.

Bananas and weight loss

For dieters, bananas offer several practical advantages:

• Low calorie density for the portion size. One medium banana provides 105 calories in a convenient, portable form that requires no preparation.
• Fiber for satiety. The 3 grams of fiber slows digestion and helps you feel satisfied between meals.
• Natural sweetness. Bananas can satisfy sugar cravings without reaching for candy or baked goods.
• Potassium support. Adequate potassium helps prevent muscle cramps during increased activity, supporting an active lifestyle.

Timing for best results

When you eat a banana matters as much as whether you eat one. Eating a banana 30–60 minutes before a workout provides readily available glucose for fuel. Alternatively, enjoy a banana as an afternoon snack to ward off energy dips without the processed sugars in candy bars or soda.

Those tracking carbohydrates for weight loss should note that riper bananas deliver faster-absorbing sugars. Less ripe bananas with a greener tint contain more resistant starch, which may support fat metabolism and help control appetite.

Which is better, eggs or bananas?

This isn’t a zero-sum question. Eggs and bananas serve different nutritional purposes, and the better choice depends on what your body needs. Souper Sage nutrition comparison tool, which compiles nutrition data from USDA and NIH sources, provides a detailed head-to-head comparison: a raw egg delivers 143 calories per 100 grams with 12.6 grams of protein, while a banana delivers 89 calories per 100 grams with 1.1 grams of protein. The protein gap is stark—eggs contain roughly 10 times more protein by weight.

Where bananas dominate is potassium. According to Souper Sage, bananas contain 160% more potassium than raw eggs (358mg vs 138mg per 100g). Bananas also provide 22.8 grams of carbohydrates per 100 grams compared to just 0.72 grams in eggs—a 32-fold difference.

Nutrition comparison table

Three core nutrients illustrate the fundamental trade-off between these foods.

The macronutrient ratios tell the story clearly. A banana draws 93% of its calories from carbohydrates, 4% from protein, and 3% from fat. An egg flips this entirely: its calories come 62% from fat, 36% from protein, and just 2% from carbohydrates. For athletes and muscle-builders prioritizing protein intake, eggs win decisively. For anyone needing quick, clean energy or looking to boost potassium intake, bananas are the practical choice.

Boiled egg vs banana

Cooking eggs changes their calorie density slightly. A boiled egg contains 155 calories per 100 grams, according to Souper Sage, compared to 143 for a raw egg. Both egg preparations remain protein powerhouses with negligible carbohydrates (1.1g per 100g) and minimal sugar (1.1g per 100g).

One large egg provides approximately 78 calories, 6g protein, 1g carbohydrates, and 5g of healthy fats, according to Ethical Nutrition. For comparison, one medium banana typically contains about 110 calories and 1g protein—meaning the egg delivers roughly 6 times more protein in a similar calorie range.

Why do some doctors say not to eat bananas?

Most doctors consider bananas a healthy part of a balanced diet. However, certain medical contexts warrant caution. People with chronic kidney disease must monitor potassium intake carefully, and since bananas are exceptionally high in potassium (450mg per medium fruit), physicians may advise limiting them to prevent hyperkalemia—a dangerous buildup of potassium in the blood.

Additionally, some nutritionists caution against specific food pairings. Combining bananas with high-oxalate foods (like sweet potatoes or certain nuts) may cause digestive discomfort in sensitive individuals, according to food safety guidance from NDTV Food. Pairing bananas with casein-rich foods like milk or cheese can also create challenging digestion in some people, as casein and banana sugars may interact uncomfortably.

Health risks of bananas

For the general population, bananas present minimal health risks. The primary concerns arise in specific scenarios:

• Kidney disease patients. Those with reduced kidney function may need to restrict potassium, including banana intake.
• Migraine triggers. Some individuals report bananas as dietary migraine triggers, possibly due to tyramine content in overripe fruit.
• Blood sugar management. People with type 2 diabetes should account for banana carbohydrates and choose smaller or less ripe specimens when possible.

Foods to avoid with bananas

Certain combinations may diminish bananas’ nutritional benefits or cause digestive issues:

• High-oxalate foods. Bananas contain moderate oxalates; pairing with foods very high in oxalates (like rhubarb or spinach) may contribute to kidney stone formation in susceptible individuals.
• Casein-rich dairy. Milk, cheese, and other dairy products containing casein protein may curdle when mixed with banana in the stomach, potentially causing bloating or discomfort.
• High-sugar foods. Eating banana alongside candy, pastries, or other high-sugar items compounds the glycemic load unnecessarily.

For most people, enjoying one banana per day as part of a varied diet poses no health risk—and likely offers more benefit than harm. If you’re on a potassium-sparing medication (common for blood pressure management), your doctor may have flagged high-potassium foods. A medium banana’s 450mg potassium could interact with your prescription—always check before making dietary changes with medication in mind.

“One medium ripe banana provides about 110 calories, 0 gram fat, 1 gram protein, 28 grams carbohydrate, 15 grams sugar (naturally occurring), 3 grams fiber, and 450 mg potassium.”

— Harvard T.H. Chan School of Public Health, Academic nutrition authority

“Unripe, green bananas are made of up to 80% starch. As the bananas ripen, this starch is converted into sugar and reduces to below 1% starch by the time the banana is fully ripe.”

— Ethical Nutrition, Nutrition educator

Related reading: How to Boil an Egg · How to Make Boiled Eggs

While medium bananas clock in at 105 calories, sizes and sugar breakdown delves into variations by size alongside sugar content for dieters.

Frequently asked questions

For anyone tracking macronutrients, bananas offer a straightforward carbohydrate source with minimal fat and a touch of fiber. Whether you prioritize eggs for protein or bananas for potassium, both foods earn their place in a varied diet. The key is matching your choice to your body’s needs: more protein after a workout, more potassium for electrolyte balance, and moderate portions whether you’re dieting or maintaining weight.