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Calories in fruit

Calories in Banana

A medium banana (118g) contains about 105 kcal, 27g of carbohydrates, and 3g of fiber. Smaller bananas can be as low as 80 kcal; large extra-large bananas reach 135 kcal.

Nutrition by portion size

Portion kcal Carbs (g) Protein (g) Fat (g) Fiber (g)
1 small banana (~101g) 90 23 1.1 0.3 2.6
1 medium banana (~118g) 105 27 1.3 0.4 3.1
1 large banana (~136g) 121 31 1.5 0.5 3.5
100g sliced banana 89 23 1.1 0.3 2.6
1 cup sliced (150g) 134 34 1.6 0.5 3.9
Glycemic index
51
Low (≤55) — slower glucose response

About these numbers

Bananas are one of the highest-volume single-serving carbohydrate sources in everyday nutrition. The calorie density (~89 kcal per 100g) is moderate, but a single medium banana typically delivers 27g of carbohydrate — more than a slice of bread.

Ripeness changes the glycemic index meaningfully: an unripe green banana has GI ~30 (mostly resistant starch); a fully ripe yellow banana has GI ~51; a brown-spotted overripe banana can reach GI ~70 (most starches have converted to sugars). For glucose control, slightly less ripe bananas are preferable. The fiber content remains roughly constant across ripeness stages.

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Frequently asked questions

How many calories are in a banana?
A medium banana (~118g, ~6-7 inches long) contains about 105 kcal. A small banana (~101g) is 90 kcal; a large (~136g) is 121 kcal; extra-large can hit 135 kcal. Size variation is substantial — measure by weight if precision matters.
Are bananas good for weight loss?
They're fine in moderation. A medium banana provides 105 kcal of mostly carbs with 3g fiber — moderate calorie density compared to other fruits. For weight loss specifically, the calorie deficit drives results, not which whole fruits you eat. Bananas are an excellent pre/post-workout snack because of their easy-to-digest carbs and potassium content (~422 mg per medium fruit).
Are bananas high in sugar?
Roughly 14g of sugar per medium banana — mostly fructose and glucose. That's about the same as a small glass of orange juice but with 3g of fiber, which slows absorption. The glycemic index is 51 (low-medium) for ripe bananas. For T2D and prediabetes, eating bananas with a protein or fat source (almond butter, Greek yoghurt) blunts the glucose response.
Are green bananas healthier than yellow?
For glucose control, slightly. Green bananas are high in resistant starch — a fiber-like compound that feeds gut bacteria, has minimal glycemic impact, and may improve insulin sensitivity. As bananas ripen, resistant starch converts to free sugars. A green banana has GI ~30; a fully ripe yellow has GI ~51; a brown-spotted overripe banana can hit GI ~70. The trade-off is taste and texture — green bananas are less sweet and starchier.
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