Bananas are extremely healthy and contain several important nutrients. A medium banana only contains 105 calories, on average. However, more than 90% of a banana is composed of carbs.
People generally know that bananas are very nutritious, but many wonder how many calories and carbs they actually contain.
This article answers those questions.
How many calories are in various sizes of bananas?
Bananas contain around 100 calories, but this can vary by the fruit size and how you consume it. Below are the calorie contents of standard banana sizes:
- Extra small (shorter than 6 inches, 81 grams): 72 calories
- Small (6–7 inches, 101 grams): 90 calories
- Medium (7–8 inches, 118 grams): 105 calories
- Large (8–9 inches, 136 grams): 121 calories
- Extra large (9 inches or longer, 152 grams): 135 calories
- Sliced (1 cup, 150 grams): 134 calories
- Mashed (1 cup, 225 grams): 200 calories
If you’re unsure about the size of your banana, you can estimate that an average banana contains about 100 calories.
About 93% of a banana’s calories come from carbs, 4% from protein, and 3% from fat.
Learn more: Are bananas fattening or weight-loss friendly?
How many carbs are in a banana?
Bananas are almost exclusively composed of water and carbs.
People who watch their carb intake are interested in knowing the carb content of their food.
Here is the carb content of standard banana sizes:
- Extra small (shorter than 6 inches, 81 grams): 19 grams
- Small (6–7 inches, 101 grams): 23 grams
- Medium (7–8 inches, 118 grams): 27 grams
- Large (8–9 inches, 136 grams): 31 grams
- Extra large (9 inches or longer, 152 grams): 35 grams
- Sliced (1 cup, 150 grams): 34 grams
- Mashed (1 cup, 225 grams): 51 grams
A banana also contains 2–4 grams of fiber, depending on its size. You can subtract 2–4 grams if you are looking for the “net” carb content (net carbs = total carbs – fiber).
Additionally, a banana’s ripeness may affect its carb content.
Generally, green or unripe bananas contain fewer digestible carbs than ripe bananas.
Learn more: How bananas affect diabetes and blood sugar levels.
Unripe (green) bananas contain more resistant starch
The main nutrient in bananas is carbs, but the carb composition changes drastically during ripening.
Unripe bananas contain high amounts of starch, and some of it is resistant starch.
Because the starch in a banana is converted to sugar during ripening, yellow bananas contain much less resistant starch than green ones.
Resistant starch is a type of indigestible carbohydrate that escapes digestion and functions like fiber in the body.
It reaches the colon undigested. There, it feeds friendly gut bacteria.
When the bacteria digest resistant starches, they form gases and short-chain fatty acids (SCFAs), which are important for digestive health.
About 95% of these SCFAs are then rapidly absorbed by the cells in the colon and used by the body for energy.
So although resistant starches will not yield as many calories as regular carbs during digestion, they may be transformed into SCFAs that provide calories later.
Therefore, green and yellow bananas may provide similar amounts of calories in the end.
Learn more about adding green bananas to your diet.
Bananas contain many other beneficial nutrients
Bananas contain good amounts of several vitamins and minerals.
One medium banana contains:
- Fiber: 3.1 grams
- Vitamin B6: 25% of the DV
- Vitamin C: 11% of the DV
- Manganese: 14% of the DV
- Potassium: 12% of the DV
- Folate: 6% of the DV
- Riboflavin (vitamin B2): 7% of the DV
FAQ
Is a banana a good carb?
Bananas are high in both sugar and fiber, depending on their ripeness. This makes them both a healthy source of energy before exercising and a food that should be monitored if you are reducing your carb and sugar intake.
Will bananas keep me full?
The soluble fiber and resistant starch in bananas contribute to a feeling of satiety, so eating a banana will keep you feeling satisfied for a longer time than many other high-carb foods.
Do bananas raise your blood sugar?
With 27 grams of carbs in one medium-sized banana, including 14 grams of sugars and 6 grams of starch, bananas do raise blood sugar. However, the fiber content will help moderate blood sugar spikes. If you are living with diabetes, check your blood sugar before and after eating bananas to monitor levels.
The bottom line
Bananas generally contain 72–135 calories and 19-35 grams of carbs, depending on their size. An average-sized banana contains about 100 calories and 25 grams of carbs.
Bananas are tasty and nutritious. They make an excellent, healthy, and low calorie snack.