A medium banana has about 110 calories. That’s based on an edible portion of roughly 126 grams (4.5 oz), which is the standard serving size used by the FDA. Of course, bananas vary quite a bit in size, so the actual count depends on what you’re holding.
Calories by Banana Size
Bananas range from under 6 inches to well over 9 inches long, and the calorie difference between the smallest and largest is meaningful if you’re tracking intake. Here’s what to expect across common sizes:
- Extra small (under 6 inches, ~80g edible): about 70 calories
- Small (6–7 inches, ~100g edible): about 90 calories
- Medium (7–8 inches, ~126g edible): about 110 calories
- Large (8–9 inches, ~135g edible): about 120 calories
- Extra large (9+ inches, ~150g edible): about 135 calories
Keep in mind that you don’t eat the peel. Research on Cavendish bananas (the common yellow variety) found the peel accounts for roughly 37% of the whole fruit’s weight, with the edible pulp making up the remaining 63%. So a banana that feels heavy on a kitchen scale will yield less actual food than you might expect. If you’re weighing bananas for calorie tracking, weigh the peeled fruit or subtract about a third from the whole-fruit weight.
What Else Is in Those Calories
Nearly all of a banana’s calories come from carbohydrates. One medium banana contains about 28 grams of total carbs, 15 grams of naturally occurring sugar, 3 grams of fiber, and just 1 gram of protein. Fat is essentially zero.
The standout micronutrient is potassium: a single medium banana delivers around 450 mg, which is roughly 10% of what most adults need daily. Bananas are also a solid source of vitamin B6, which supports your immune system and helps your body metabolize protein and carbs. The 3 grams of fiber, while modest, contributes to the feeling of fullness that makes bananas a more satisfying snack than foods with the same calorie count but less fiber.
How Ripeness Changes the Nutrition
A green banana and a spotty brown banana have roughly the same number of total calories, but the type of carbohydrate inside shifts dramatically as the fruit ripens. Unripe bananas store 20–25% of their pulp weight as starch. During ripening, that starch breaks down into simple sugars like glucose, fructose, and sucrose. By the time a banana is fully ripe, its starch content has dropped from around 25% to just 1%.
This matters for two reasons. First, ripe bananas taste sweeter because they literally contain more sugar, even though the total calorie count hasn’t changed much. Second, green bananas contain a significant amount of resistant starch, a type of carbohydrate your body can’t fully digest. Resistant starch passes through your small intestine intact and feeds beneficial gut bacteria in your colon, functioning similarly to soluble fiber. Because it isn’t fully absorbed, a green banana may deliver slightly fewer usable calories than a ripe one, though the difference is small enough that calorie labels don’t distinguish between them.
Ripeness and Blood Sugar
The starch-to-sugar conversion also affects how quickly a banana raises your blood sugar. The glycemic index of a banana ranges from the low 40s when green to the low 60s when fully ripe. For context, anything under 55 is considered low glycemic, and 56–69 is medium. So a green banana is a low-glycemic food, while a very ripe banana tips into the medium range.
If you’re managing blood sugar, choosing slightly less ripe bananas (firm, yellow, with minimal brown spots) gives you a slower glucose response. Pairing a ripe banana with a source of protein or fat, like nut butter or yogurt, also blunts the sugar spike by slowing digestion.
How Bananas Compare to Other Fruit
At 110 calories for a medium fruit, bananas are on the higher end for common snacking fruits. A medium apple has about 95 calories, a medium orange around 65, and a cup of strawberries roughly 50. The difference comes down to water content: bananas are denser and less watery than most fruit, which concentrates both their calories and their nutrients into a smaller package. That density is also why bananas feel more filling than a handful of grapes with the same calorie count.
For anyone tracking macros or watching carb intake, the key number to remember is 28 grams of carbs per medium banana. That’s roughly equivalent to two slices of white bread, though the banana comes with more fiber, more potassium, and no added ingredients.