nutrition

How Many Carbs Are in a Banana? By Size, Ripeness and Net Carbs

A doctor’s look at the real carb count in a banana, how much of it is sugar, how much is fiber and starch, how ripeness changes all three, and how to eat one without riding a blood sugar roller coaster.

By Dr. Josh Axe, DC, DNM, CNS·Medically reviewed by the DrAxe.com Medical Advisory Board·22-min read

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Published May 29, 2024Last updated Sep 23, 2026Editorial policyMedical review policyFact-checking policy

How many carbs are in a banana? A medium banana, 7 to 7-7/8 inches long and about 118 grams, has roughly 27 grams of total carbohydrate, including about 3 grams of fiber and 14 grams of naturally occurring sugars, for about 24 grams of net carbs and 105 calories 1. A small banana drops that to about 23 grams of carbs; an extra-large one pushes past 34.

That is the number most people came for. The more useful number is the one almost nobody publishes: how much of that carbohydrate is sugar versus starch changes dramatically as the banana ripens on your counter, and that shift matters more for your blood sugar than the size of the fruit does.

The short version

A medium banana is a moderate-carb, low-glycemic whole food: about 27 grams of carbohydrate, 3 grams of fiber and 14 grams of naturally occurring sugar, with a quarter of a day’s vitamin B6 and 9% of your potassium attached. It is too carb-dense for a strict ketogenic diet and comfortably inside a normal whole-food diet. The variable almost nobody accounts for is ripeness, which converts starch into sugar without changing the number on the label, and the two habits that matter most are pairing the fruit with protein and moving afterward.

At a glance

Carbs, medium banana (118 g)

About 27 g total, 3 g fiber, 24 g net

Sugars

About 14 g, all naturally occurring

Calories

About 105

Glycemic index

About 51 when ripe, 42 when slightly under-ripe, both in the low band

Biggest variable

Ripeness, not size

Best for

Potassium, vitamin B6, fiber, pre- and post-workout fuel

Watch

Eaten alone on an empty stomach, a very ripe banana is one of the faster-digesting fruits you can pick

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Carbs in a Banana by Size

Size	Weight	Total carbs	Fiber	Net carbs	Sugars	Calories
Extra small (under 6”)	81 g	18.5 g	2.1 g	16.4 g	9.9 g	72
Small (6” to 6-7/8”)	101 g	23.1 g	2.6 g	20.4 g	12.4 g	90
Medium (7” to 7-7/8”)	118 g	27.0 g	3.1 g	23.9 g	14.4 g	105
Large (8” to 8-7/8”)	136 g	31.1 g	3.5 g	27.5 g	16.6 g	121
Extra large (9” or longer)	152 g	34.7 g	4.0 g	30.8 g	18.6 g	135
1 cup, sliced	150 g	34.3 g	3.9 g	30.4 g	18.3 g	134
1 cup, mashed	225 g	51.4 g	5.9 g	45.5 g	27.5 g	200

Values calculated from USDA FoodData Central for raw bananas and USDA’s own portion weights 1.

Five Things Worth Knowing Before You Read Further

Size swings the count by about 16 grams. An extra-small banana and an extra-large one are nearly a two-fold difference in carbohydrate. Most people eat somewhere in the middle and call it “a banana.”
A banana is mostly water. Around 75% by weight 1. The carb number sounds high next to a strawberry only because a banana is denser food.
Ripeness converts starch into sugar. In one analysis of retail bananas, total starch fell from about 4.5 grams per 100 grams at the slightly ripe stage to about 0.5 grams once overripe, while sugars climbed 2.
The glycemic index sits lower than the reputation. A ripe banana tests around 51, and a slightly under-ripe one around 42, both inside the low band of 55 and under 3. Fruit as a category is consistently low-GI worldwide 4.
How you eat it changes the response more than which one you pick. Pairing and timing do more work than counting.

How Many Carbs Are in a Banana?

Quick answer

A medium banana (118 grams) contains about 27 grams of total carbohydrate, of which roughly 3 grams is dietary fiber and about 14 grams is naturally occurring sugar. The rest is mostly starch. That works out to about 24 grams of net carbs and 105 calories per medium banana.

The USDA’s reference entry for raw bananas gives 22.84 grams of carbohydrate per 100 grams, with 2.6 grams of fiber and 12.23 grams of total sugars 1. Every number in the size table above comes from scaling that entry to USDA’s own measured portion weights, which is why the counts differ from the round “27 grams” you see repeated everywhere without a size attached.

Two practical points come out of that table. The first is that “a banana” is not a unit of measurement. The 9-inch banana at the bottom of the bunch carries nearly 90% more carbohydrate than the stubby one at the top. If you are tracking carbs at all closely, weigh the fruit once or twice and you will calibrate your eye quickly.

The second is that bananas get counted as a big carb food mostly because they are big fruit. Per 100 grams, a banana carries about 23 grams of carbohydrate against roughly 17 for grapes, 14 for an apple and 12 for an orange 1 5. That is a real difference, but it is a difference of degree, not of kind.

How Many Net Carbs Are in a Banana?

Quick answer

A medium banana has about 24 grams of net carbs, calculated as 27 grams of total carbohydrate minus 3.1 grams of fiber. A small banana comes in near 20 grams of net carbs, and an extra-large one near 31 grams.

Net carbs is a working number, not an official one. You take total carbohydrate and subtract the fiber, on the reasoning that fiber is not absorbed as glucose. For most whole foods that is a reasonable simplification. For a banana it is close enough to be useful.

Where the shortcut gets shaky is with unripe fruit. Resistant starch behaves in your body much more like fiber than like starch, and depending on which laboratory method is used, some of it gets counted as fiber and some of it does not 2. A green-tipped banana therefore has fewer “effective” carbs than the label math suggests. I would not try to calculate that difference to the gram. I would simply know that the greener banana is the gentler one.

What Kind of Carbs Are in a Banana?

Quick answer

The carbohydrate in a ripe banana is roughly half simple sugars, split between glucose, fructose and sucrose, plus starch and about 3 grams of fiber per medium fruit. USDA data for raw bananas lists 4.98 grams of glucose, 4.85 grams of fructose, 2.39 grams of sucrose and 5.38 grams of starch per 100 grams 1.

This is the part of the question that gets skipped, and it is where the interesting answer lives.

Sugars (about 12 g per 100 g). Nearly an even split of glucose and fructose, with a smaller amount of sucrose. These are the fast-absorbing carbohydrates, and they are what makes a very ripe banana taste like candy.
Starch (about 5 g per 100 g in a ripe fruit, far higher when green). Long chains of glucose. In a green banana most of this is resistant starch, which passes through the small intestine largely undigested.
Fiber (about 2.6 g per 100 g). A mix of pectin and resistant starch that slows digestion and feeds the bacteria in your colon.

None of this is added sugar, and that distinction is the whole ballgame. There is a real difference between naturally occurring sugars that arrive packaged with fiber, potassium and vitamin C, and the added sugars in a soda or a pastry that arrive with nothing. Whole fruit is the format your body was built to handle. If you are craving something sweet, reach for fruit instead of the dessert; even the sweeter fruits like watermelon and bananas are a better answer than added sugar. I walk through where the added sugar is actually hiding in 11 foods with shockingly high amounts of sugar on the Dr. Axe Show.

Does Ripeness Change the Carbs in a Banana?

Quick answer

Ripeness does not change the total carbohydrate much, but it changes the kind of carbohydrate substantially. As a banana ripens, starch converts to sugar. Measured across retail bananas, total starch fell from about 4.5 grams per 100 grams at the slightly ripe stage to 2.5 grams at ripe and 0.5 grams once overripe, while total sugars rose from about 15 grams to 17 grams and fiber fell from about 5 grams to under 2 grams 2.

Here is where a banana stops being a single food. A green banana and a brown-spotted banana have almost the same carb count on paper and behave like two different foods in your body.

Ripeness	What it looks like	Starch	Sugars	Fiber	How it behaves
Green / unripe	Firm, green skin, hard to peel	Highest, much of it resistant	Lowest	Highest	Slow, gut-feeding, minimal glucose rise
Slightly ripe	Yellow with green tips	4.5 g/100 g	15 g/100 g	5 g/100 g	Balanced, my preferred stage
Ripe	Fully yellow	2.5 g/100 g	17 g/100 g	3.7 g/100 g	Sweeter, faster
Overripe	Brown-flecked, soft	0.5 g/100 g	17 g/100 g	1.9 g/100 g	Fastest, most dessert-like

Retail-market values from Phillips et al., 2021 2. Fiber figures use the modified enzymatic-gravimetric method, which captures resistant starch as fiber, so they run higher than the standard USDA fiber number.

The ripening process is a plant slowly cashing in its own savings account. Enzymes break the stored starch down into simple sugars to make the fruit attractive to whatever eats it and spreads the seeds. Studies tracking bananas and plantains through ripening find the same pattern of falling starch and rising sugars, alongside changes in antioxidant compounds 6.

The practical translation is short. If blood sugar is your concern, buy your bananas greener and eat them before they speckle. If you want the fastest available fuel, say ten minutes before a hard workout, the spotted one is the right tool.

What Is the Glycemic Index of a Banana?

Quick answer

A ripe banana has a glycemic index of about 51 and a slightly under-ripe one about 42, both of which fall inside the low band of 55 and under. The corresponding glycemic loads are roughly 13 and 11, which is moderate 3.

Glycemic index ranks how fast a food raises blood glucose compared with pure glucose at 100. Under 55 counts as low, 56 to 69 as medium, 70 and up as high. At around 51 the banana lands inside the low band, which surprises people who have been told to avoid it. The international GI tables make the same point at the category level: fruits are usually low-GI foods, with values that hold up consistently around the world, while cereals and cereal products vary widely 4.

Glycemic load is the number I pay more attention to, because it accounts for how much you eat. Multiply the GI by the grams of available carbohydrate and divide by 100, and a medium banana comes out near 13. A white bagel, for comparison, runs several times that.

Two caveats belong here. Published GI values for a single food span a range across laboratories, and bananas move with both ripeness and cultivar, so treat 51 as a center of gravity rather than a fixed property of the fruit. And glycemic index is measured on the food eaten alone, in isolation, on an empty stomach, which is close to the worst way to eat one. It tells you about the food. It does not tell you much about your meal.

Do Bananas Spike Your Blood Sugar?

Quick answer

A banana raises blood glucose, as any carbohydrate-containing food does, but a moderate amount and less than most people expect. The rise depends far more on ripeness, portion, what you eat alongside it, and how you move afterward than on the fruit itself.

That 3 o’clock crash, the one where your eyes get heavy and you would trade anything for a nap, is often a blood sugar roller coaster. A refined-carb meal spikes glucose, then it drops, and the drop feels exactly like exhaustion. A banana eaten alone on an empty stomach can play a small part in that pattern. A banana eaten correctly does not.

Three levers flatten the curve, and all three are free:

Never eat carbs naked. Always pair them with protein or fat. A banana with a scoop of almond butter, a handful of walnuts or alongside eggs is a different meal from a banana by itself. Sequencing research points the same direction: eating protein and vegetables before the carbohydrate portion of a meal blunts the glucose rise in healthy adults, though the trials so far are small and short 7.
Walk for 10 to 15 minutes after you eat. Interrupting sitting with short, regular activity breaks measurably lowers postprandial glucose and insulin 8. This is the highest-return habit on the list, and it costs you a lap around the block.
Pick the greener fruit. More resistant starch, less sugar, slower absorption.

If you want the fuller picture on how food choices move your numbers, our guides to normal blood sugar ranges and the low glycemic diet go deeper than this page can.

Are Bananas OK If You Have Diabetes or Insulin Resistance?

Quick answer

For most people with type 2 diabetes or insulin resistance, a small-to-medium banana eaten with protein or fat fits comfortably in a day’s carbohydrate budget. Whole fruit intake, unlike fruit juice, is associated with lower risk of type 2 diabetes rather than higher. Anyone managing blood glucose with medication should confirm their own portion with their clinician and a glucose meter.

The population data here runs against the intuition. Across three large prospective cohorts following more than 187,000 people for a combined 3.5 million person-years, greater consumption of whole fruits was associated with a lower risk of type 2 diabetes, while greater fruit juice consumption was associated with a higher risk 9. The effect varied by fruit, with blueberries, grapes and apples showing the strongest associations. Bananas came in at a hazard ratio of 0.95 per three servings a week, a small but statistically significant association with lower risk rather than higher.

That fits the way I teach this. Fruit contains sugar, but it arrives with fiber, vitamins, minerals and water, and the fiber slows sugar absorption. Sugar that comes packaged inside a whole food is a different exposure than sugar that comes stripped of everything else.

My read: population associations are not the same as your personal glucose response, which varies more between individuals than most nutrition advice admits. If you are managing insulin resistance, metabolic syndrome or diabetes, the answer is not to trust an article, including this one. Test. Eat your usual banana with your usual breakfast, check your glucose at 60 and 120 minutes, and let your own data settle the question.

What I would steer you toward in the meantime: a smaller, greener banana; always paired with protein; earlier in the day rather than at night. My general framework for blood sugar is high protein, high fiber, moderate fat and low-to-moderate carbohydrate, and a banana fits inside that framework without difficulty.

This is general education, not a treatment plan. Nutrition changes work alongside, never instead of, the care of a qualified clinician, and anyone on insulin or a glucose-lowering medication should not adjust carbohydrate intake without medical guidance.

Are Bananas Keto or Low-Carb?

Quick answer

No. At about 24 grams of net carbs, one medium banana would use most or all of a standard 20 to 30 gram daily ketogenic carbohydrate allowance. Bananas fit a moderate-carb or liberal low-carb approach, but not a strict ketogenic one.

The arithmetic decides this one. On a 20-gram net carb ceiling, a single medium banana puts you over budget before anything else on the plate. Even at a more generous 50 grams a day, you have spent nearly half of it on one piece of fruit.

That does not make the banana a bad food. It makes it the wrong food for that particular diet. Berries, avocado and rhubarb are the fruits that fit a ketogenic pattern, and an avocado carries just under 2 grams of net carbs per 100 grams against a banana’s 20 5.

For what it is worth, I do not think most people need to be in ketosis. My standard recommendation is high protein, high fiber, moderate fat and low-to-moderate carbohydrate rather than strict keto, and in that pattern a banana is an easy yes.

What Else Is in a Banana Besides Carbs?

Quick answer

A medium banana delivers about 422 mg of potassium (9% of the Daily Value), 0.43 mg of vitamin B6 (25% DV), 32 mg of magnesium (8% DV), 0.32 mg of manganese (14% DV) and 10 mg of vitamin C (11% DV), for 105 calories 1.

Nutrient	Per medium banana (118 g)	% Daily Value
Calories	105	n/a
Carbohydrate	27.0 g	10%
Fiber	3.1 g	11%
Total sugars	14.4 g	n/a
Protein	1.3 g	3%
Fat	0.4 g	1%
Potassium	422 mg	9%
Vitamin B6	0.43 mg	25%
Vitamin C	10.3 mg	11%
Magnesium	32 mg	8%
Manganese	0.32 mg	14%
Folate	24 mcg	6%

Calculated from USDA FoodData Central values for raw bananas 1. Percent Daily Values are based on FDA adult reference values.

The vitamin B6 figure is the one that surprises people. A quarter of a day’s requirement from one piece of fruit is a strong showing for a nutrient involved in neurotransmitter production and dozens of enzyme reactions.

Potassium deserves its own note, because the banana’s reputation slightly oversells it. A medium banana gives you around 422 mg against a 4,700 mg Daily Value, so roughly 9% 1 10. That is respectable, and it is well short of the potassium bomb the cereal-box version of nutrition suggests; avocado, white beans and leafy greens all beat it per serving. Raising potassium intake does matter. Pooled data from 22 randomized trials found that higher potassium intake lowered systolic blood pressure by about 3.5 mm Hg in adults, an effect seen in people with hypertension but not in those without, with no adverse effect on kidney function or blood lipids. Cohort data in the same review linked higher potassium intake to a 24% lower risk of stroke 11. Just do not expect one banana to do that job. Our list of potassium-rich foods shows where the bigger sources are.

Green vs. Yellow: Which Banana Should You Eat?

Quick answer

Green and slightly green bananas are higher in resistant starch, which resists digestion in the small intestine and ferments in the colon into short-chain fatty acids that feed the gut lining. Fully ripe and overripe bananas are sweeter, faster-digesting and better suited to fueling exercise. For blood sugar and gut health, greener wins.

A green banana looks like unripe fruit, but biologically it behaves more like a prebiotic supplement that happens to come in a peel.

That is not a figure of speech. Resistant starch reaches the colon intact, where bacteria ferment it into short-chain fatty acids including butyrate, the primary fuel for the cells lining your colon and a signaling molecule with effects well beyond the gut 12 13. Green bananas carry more resistant starch than any other common food: green banana flour runs around 30% resistant starch against roughly 70% total starch on a dry basis, which is why food scientists keep reaching for it, and reviews describe its potential as a prebiotic for gut health 14. Fiber intake in general is one of the better-supported levers in nutrition science, with pooled trial and cohort data tying higher intakes to lower rates of cardiovascular disease, type 2 diabetes and colorectal cancer 15.

The evidence on the glucose side is encouraging without being settled. A meta-analysis of resistant starch trials in people with type 2 diabetes or prediabetes found improvements in glycemic response, with the size of the effect depending on the type of resistant starch used and considerable variation between trials 16. The type in a green banana is not identical to the types used in most of that research, so I read it as supporting rather than proving the case.

I lean toward buying bananas with green tips and eating them within a couple of days. If you want a concentrated version, green banana flour and plantains deliver considerably more resistant starch than fresh fruit does. The same principle drives my recommendation of prebiotic foods generally: feed the bacteria, and they feed you back. If you want the deeper mechanism, our resistant starch guide covers the food sources and the research.

Are Banana Carbs Good for Workouts?

Quick answer

Yes. The carbohydrate in a ripe banana is well-suited to fueling and recovering from exercise, and it has been tested head to head against sports drinks. In cyclists, bananas performed comparably to a 6% carbohydrate beverage for supporting performance during prolonged exercise, while delivering additional nutrients the drink did not 17.

This is the one context where I want the ripe, sweet banana rather than the green one. Fast carbohydrate is the point.

A follow-up crossover trial compared bananas with a sugar beverage and with water alone after heavy exertion, and found the banana produced favorable shifts in metabolic recovery markers relative to the sugar drink, which the researchers attributed in part to the fruit’s other compounds 18. Both trials were small and industry-supported, which is worth knowing, and neither one makes the banana a magic recovery food. What they do support is the simple claim that whole fruit is at least as good as an engineered sports drink for this job, and it costs a fraction as much.

A practical way to use that: half a banana about 30 minutes before training, the other half with a protein source within an hour afterward.

Banana Carbs Compared With Other Fruits

Quick answer

Per 100 grams, a banana carries more carbohydrate than most common fruits: about 23 grams, against 17 for grapes, 15 for mango and pear, 14 for apple, 12 for orange and under 8 for strawberries and watermelon. Avocado sits far below all of them at under 2 grams of net carbs.

Fruit (per 100 g)	Total carbs	Fiber	Net carbs	Sugars	Calories
Banana	22.8 g	2.6 g	20.2 g	12.2 g	89
Grapes (American)	17.2 g	0.9 g	16.3 g	16.3 g	67
Pear	15.2 g	3.1 g	12.1 g	9.8 g	57
Mango	15.0 g	1.6 g	13.4 g	13.7 g	60
Blueberries	14.5 g	2.4 g	12.1 g	10.0 g	57
Apple, with skin	13.8 g	2.4 g	11.4 g	10.4 g	52
Orange	11.8 g	2.4 g	9.4 g	9.4 g	47
Strawberries	7.7 g	2.0 g	5.7 g	4.9 g	33
Watermelon	7.6 g	0.4 g	7.2 g	6.2 g	30
Avocado	8.5 g	6.7 g	1.8 g	0.7 g	160

USDA FoodData Central values for raw fruit, per 100 grams (about 3.5 ounces) for a like-for-like comparison 1 5. Typical serving sizes vary, so a cup of strawberries and a whole banana are closer than this table implies.

Read that table carefully before you swear off bananas. The differences are meaningful if you are counting to 20 grams a day. They are close to irrelevant if you are eating a whole-food diet and want to know whether fruit is “allowed.”

If berries are available, take the berries. They carry more fiber, less sugar and more antioxidants per bite, and that is why I rank them at the top of the fruit list. Bananas are still a good food, and they are always the better answer than a cookie.

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How to Fit a Banana Into Your Day

Quick answer

Choose a small-to-medium banana with green at the tips, pair it with protein or fat, eat it earlier in the day rather than late at night, and walk for 10 minutes afterward. Those four moves matter more than the carb count on the label.

Pair it, always. A banana with almond butter, walnuts, Greek yogurt or a protein shake. One serving of fruit alongside protein makes a solid breakfast; one banana alone is a snack that leaves you hungry an hour later.
Go earlier, not later. Carbohydrate is best tolerated in the first two-thirds of your day. Evening is when I keep carbohydrate lowest.
Buy them greener. More resistant starch, less sugar, and they will ripen on your counter anyway.
Watch the drift into dessert. Banana bread, banana chips and smoothies with three bananas in them are a different food category. A cup of mashed banana in a smoothie carries 51 grams of carbohydrate before you add anything else.
Freeze the ones going brown. Frozen banana blended with cocoa and a scoop of protein powder is a legitimate dessert replacement, and the corresponding sugar comes with fiber attached.
Do not eat it naked and sedentary. Standing up after a meal is the difference between a bump and a spike.

If you need the wider framework rather than one fruit, our guides to high-fiber foods and the glycemic index are the natural next reads, and the full nutrient profile lives on our banana nutrition page.

The bottom line

How many carbs are in a banana?

About 27 grams in a medium one, with 3 grams of fiber and 14 grams of naturally occurring sugar behind that number.

The more useful answer is that the count is the least interesting thing about the fruit. Ripeness decides whether you are eating a slow, gut-feeding resistant starch or a fast, dessert-like sugar, and it does that without changing the carb total on the label. Pairing and movement decide what your blood glucose does next.

The real limit is worth stating plainly: a banana is a carbohydrate-dense fruit, it will not fit a strict ketogenic diet, and if your glucose runs high you should confirm your own response with a meter rather than trusting any general recommendation, including mine.

For most people, none of that is a reason to avoid one. Buy your bananas with green tips. Eat them with protein. Walk for ten minutes afterward. Then stop worrying about the fruit and spend the energy on the added sugar in everything else you eat, which is where the real problem has been the whole time.

Frequently asked questions

How Many Carbs Are in a Medium Banana?

About 27 grams of total carbohydrate, including roughly 3.1 grams of fiber and 14.4 grams of naturally occurring sugars, based on USDA data for a 118-gram medium banana. That works out to about 24 grams of net carbs and 105 calories 1.

How Many Carbs Are in a Large Banana?

A large banana, 8 to 8-7/8 inches and about 136 grams, carries about 31.1 grams of total carbohydrate, 3.5 grams of fiber and 27.5 grams of net carbs, for roughly 121 calories 1.

How Many Carbs Are in a Small Banana?

A small banana, 6 to 6-7/8 inches and about 101 grams, has roughly 23.1 grams of total carbohydrate, 2.6 grams of fiber and 20.4 grams of net carbs, for about 90 calories 1.

How Many Net Carbs Are in a Banana?

A medium banana has about 24 grams of net carbs (27 grams total carbohydrate minus 3.1 grams of fiber). A small banana comes in near 20 grams and an extra-large near 31 grams 1.

How Much Sugar Is in a Banana?

A medium banana contains about 14 grams of naturally occurring sugar, split fairly evenly between glucose and fructose with a smaller amount of sucrose. None of it is added sugar, and it arrives packaged with fiber, potassium and vitamin C 1.

Are Bananas High in Carbs?

Bananas are higher in carbohydrate than most common fruits, at about 23 grams per 100 grams compared with 14 for an apple and 12 for an orange. In the context of a whole-food diet, that is a moderate amount, and the fiber, potassium and vitamin B6 that come with it change the calculation 1 5.

Are Bananas Keto-Friendly?

No. One medium banana carries about 24 grams of net carbs, which would use most or all of a standard 20 to 30 gram daily ketogenic allowance. Berries, avocado and rhubarb are the fruits that fit a ketogenic pattern 1.

Can I Eat a Banana on a Low-Carb Diet?

On a moderate low-carb approach of 100 to 150 grams of carbohydrate a day, a small banana fits without difficulty. On a strict ketogenic plan under 30 grams, it does not. Portion size and ripeness are the levers if you want to make it work 1.

What Is the Glycemic Index of a Banana?

Published tables put the banana at about 51, which falls in the low band (under 55). Riper bananas test higher than greener ones because ripening converts starch into sugar, and values vary across studies by variety and ripeness 3 4.

Do Bananas Raise Blood Sugar?

A banana raises blood glucose the way any carbohydrate food does, moderately rather than sharply. Ripeness, portion and what you eat alongside it move the response more than the fruit itself. Pairing the banana with protein or fat and walking afterward flattens the curve considerably 7 8.

Can Diabetics Eat Bananas?

Most people with type 2 diabetes can include a small-to-medium banana as part of a planned carbohydrate budget, ideally paired with protein and eaten earlier in the day. Large cohort studies link whole fruit intake to lower rather than higher diabetes risk. Confirm your own portion with your clinician and a glucose meter, especially if you take glucose-lowering medication 9.

Do Green Bananas Have Fewer Carbs?

Green bananas have a similar total carbohydrate count but a very different composition: much more resistant starch and much less sugar. Because resistant starch behaves more like fiber than like starch, a green banana produces a smaller glucose rise than a fully ripe one 2 16.

Is a Banana a Good Pre-Workout Food?

Yes. A ripe banana is fast-digesting carbohydrate with potassium attached, and in trials with cyclists it performed comparably to a carbohydrate sports drink for supporting prolonged exercise. Half a banana about 30 minutes before training works well for most people 17.

How Many Carbs Are in a Cup of Sliced Banana?

A cup of sliced banana weighs about 150 grams and carries roughly 34.3 grams of total carbohydrate, 3.9 grams of fiber and 30.4 grams of net carbs. A cup of mashed banana is heavier at 225 grams and carries about 51.4 grams of carbohydrate 1.

Are Bananas Fattening?

No single food causes weight gain on its own; total intake and overall diet pattern decide that. A medium banana is 105 calories with about 3 grams of fiber attached, which is a modest contribution to a day’s intake 1. The banana products worth watching are the concentrated ones: banana bread, banana chips and multi-banana smoothies.

Which Fruit Has the Fewest Carbs?

Among common fruits, avocado is lowest by a wide margin at under 2 grams of net carbs per 100 grams, followed by strawberries at about 5.7 grams and watermelon at about 7.2 grams. Berries generally sit at the low end and are the fruits I recommend most often 5.

Freshness & method note

August 2026 — This revision rebuilds the page around USDA FoodData Central values for every banana size, corrects the potassium figure to a per-banana rather than per-100-gram basis, adds a ripeness-stage carbohydrate table from 2021 retail-market analysis, adds glycemic index and glycemic load context, and adds sections on resistant starch, exercise fueling and blood sugar practice.

References

Dr. Josh Axe, DC, DNM, CNS

Doctor of Natural Medicine · Founder, DrAxe.com

Dr. Axe is a certified doctor of natural medicine, clinical nutritionist, and multiple New York Times bestselling author. He has spent 20+ years in clinical practice helping people heal at the root cause and founded one of the most-visited natural-health platforms in the world.

Read the full bio →

Dr. Josh Axe is the founder of DrAxe.com and co-founder of Ancient Nutrition. DrAxe.com may earn a commission when you purchase supplements, books, programs, lab tests, or other products linked in or related to this article, including brands Dr. Axe is affiliated with. These relationships never determine which studies are cited, how the evidence is presented, or the guidance given. Scientific claims are sourced to the peer-reviewed references listed above, and our editorial and medical-review processes operate independently of commercial relationships.

This content is for educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure, or prevent any disease. Carbohydrate needs vary by individual; if you have diabetes, prediabetes, kidney disease or another health condition, talk with a qualified healthcare provider before making significant changes to the carbohydrate in your diet, and never adjust medication on your own.