A medium banana (about 118 grams) contains roughly 27 to 28 grams of total carbohydrates. That breaks down into 15 grams of natural sugar, 3 grams of fiber, and the rest as starch. If you subtract the fiber to calculate net carbs, you’re looking at about 25 grams per banana.
Carbs by Banana Size
Not all bananas are the same size, and a couple of inches makes a real difference in carb count. A small banana contains about 23 grams of carbohydrates, while an extra-large banana can pack roughly 35 grams. If you’re tracking carbs for blood sugar management or a specific diet, choosing a smaller banana is a simple way to cut the number down.
Per 100 grams of fruit, bananas contain about 23 grams of carbohydrates. That’s significantly more carb-dense than many other popular fruits. Apples, for comparison, have about 14 grams of carbs per 100 grams, making bananas roughly 65% higher in carbohydrate density.
Sugar, Starch, and Fiber Breakdown
The 27 to 28 grams of carbs in a medium banana aren’t all the same type, and the ratio shifts dramatically depending on ripeness. A ripe yellow banana gets most of its carbs from simple sugars: sucrose makes up the largest share, with smaller amounts of glucose and fructose. The 3 grams of fiber include a type called pectin, which softens stools and supports digestive regularity.
The remaining carbs come from starch, though in a ripe banana that’s a very small portion. A medium ripe banana has about 110 calories, no fat, and 1 gram of protein, so carbohydrates account for nearly all of its energy content. It also delivers 450 milligrams of potassium, which is roughly 10% of the daily recommended intake for most adults.
How Ripeness Changes the Carb Profile
This is where bananas get interesting. A green, unripe banana is mostly starch, with starch making up 70 to 80% of its dry weight. Much of that starch is “resistant starch,” meaning it passes through your upper digestive tract without being broken down. Your body treats resistant starch more like fiber than like sugar, so it has a smaller effect on blood sugar levels.
As a banana ripens and turns yellow, then spotted, enzymes convert that starch into simple sugars. By the time a banana is fully ripe, only about 1% of its dry weight is starch. The total carbohydrate count stays roughly the same, but the composition flips almost entirely from starch to sugar. The pectin content also drops as bananas ripen, meaning less fiber overall.
In practical terms, a greener banana will raise your blood sugar more slowly and keep you feeling full a bit longer. A very ripe, spotted banana delivers the same carbs but in a form your body absorbs faster. Neither is “bad,” but if you’re managing blood sugar, greener bananas give you a gentler curve.
Bananas and Blood Sugar Management
If you’re watching your carb intake, bananas are one of the higher-carb fruits, but they’re far from off-limits. The American Diabetes Association notes that people with diabetes can include bananas as part of a balanced diet. The key is portion awareness. Pairing a banana with a source of protein or fat (like peanut butter or yogurt) slows digestion and blunts the blood sugar spike.
Choosing a small banana over a large one cuts your carb intake by about 12 grams, which is a meaningful difference if you’re aiming for a specific carb target per meal. Opting for a slightly less ripe banana adds back some resistant starch and fiber, further moderating the blood sugar response.
How Bananas Compare to Other Fruits
Bananas sit on the higher end of the carb spectrum for fresh fruit. Here’s how a 100-gram serving compares:
- Banana: 23 g carbs
- Apple: 14 g carbs
- Orange: 12 g carbs
- Strawberries: 8 g carbs
Keep in mind that a medium banana weighs about 118 grams, while a medium apple is closer to 180 grams. So the per-fruit difference is even larger than the per-100-gram numbers suggest. If you’re looking for a lower-carb fruit swap, berries consistently come in at about a third of the carbs per serving.