How many carbs are in a banana?

A medium banana (118g) has 26.9g total carbohydrates and 23.8g net carbs. Net carbs are calculated by subtracting 3.1g of dietary fiber from total carbs. A small banana (100g) has about 20.2g net carbs; a large banana (136g) has about 27.4g net carbs.

How many carbs in half a banana?

Half a medium banana (about 60g) has 12.1g net carbs and 53 calories (12.4g total carbs minus 1.5g fiber).

How much sugar is in a banana?

A medium banana contains 14.4g of sugar. This natural sugar (primarily fructose and glucose) is why bananas are sweet and why they have a relatively high glycemic impact compared to other fruits.

How many carbohydrates are in a banana?

A medium banana (118g) contains 26.9g of total carbohydrates — 3.1g dietary fiber, 14.4g natural sugar, and the remainder as starch. Net carbohydrates (total carbohydrates minus fiber) equal 23.8g. Per 100g, bananas have 22.8g total carbohydrates and 20.2g net carbohydrates.

How Many Carbs in a Banana?

Q: Are bananas keto friendly?

No — bananas are not keto friendly. A medium banana has 23.8g net carbs, which exceeds the typical daily keto limit of 20g. Even half a banana (12.1g net carbs) uses over half a day's keto budget. Berries like strawberries or raspberries are much better low-carb alternatives.

23.8g

Net Carbs — 1 Medium Banana (118g)

🟥 High Carbs — not keto friendly

Total carbs: 26.9g | Fiber: 3.1g | Calories: 105 kcal

23.8g

Net Carbs

105

Calories

1.3g

Protein

0.3g

Fat

Calories	105 kcal
Total Carbohydrates	26.9g
Dietary Fiber	3.1g
Sugars	14.4g
→ Net Carbs	23.8g
Protein	1.3g
Total Fat	0.3g

Calories	89 kcal
Total Carbohydrates	22.8g
Dietary Fiber	2.6g
Sugars	12.2g
→ Net Carbs	20.2g
Protein	1.1g
Total Fat	0.3g

Banana Carbs by Size

Size	Weight	Net Carbs	Total Carbs	Calories
½ banana	60g	12.1g	13.7g	53
Medium banana ★	118g	23.8g	26.9g	105
Large banana	136g	27.4g	31.0g	121
Per 100g	100g	20.2g	22.8g	89

Carbohydrates in a Banana

A medium banana contains 26.9g of total carbohydrates per serving (118g). Those carbohydrates break down into three components: 3.1g dietary fiber, 14.4g natural sugars (fructose and glucose), and the remainder as starch. Per 100g, a banana has 22.8g of carbohydrates.

Of all common fruits, bananas rank among the highest in carbohydrates — roughly 3–5× more than strawberries or raspberries. The carbohydrate composition also shifts as bananas ripen: starch converts to sugar, raising the glycemic index while keeping total carbohydrates similar. A greener banana and a very ripe banana have nearly identical carbohydrate counts but different effects on blood sugar.

Net carbohydrates (the figure most relevant for low-carb dieting) are calculated by subtracting fiber from total carbohydrates: 26.9g − 3.1g = 23.8g net carbs per medium banana. This is the carbohydrate figure that matters for keto tracking.

The Quick Answer

A medium banana (118g) has 23.8g net carbs and 105 calories. Net carbs are calculated by subtracting 3.1g of dietary fiber from 26.9g of total carbohydrates. Bananas are one of the higher-carb fruits — a single medium banana nearly hits the entire daily net carb limit on strict keto.

All nutrition data is sourced from the USDA FoodData Central database.

Are Bananas Keto Friendly?

No. A medium banana's 23.8g net carbs exceeds the typical strict keto limit of 20g per day. Even half a banana (12.1g net carbs) accounts for over half a day's keto budget. Bananas are not a good fit for ketogenic diets.

If you want a low-carb fruit fix, strawberries (5.7g/100g), blackberries (4.9g/100g), and blueberries (12.1g/100g in small portions) are all better options.

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Banana Serving Sizes

How Banana Net Carbs Are Calculated

Net carbs = Total Carbs − Dietary Fiber. For a medium banana: 26.9g − 3.1g = 23.8g net carbs. Fiber is excluded because it passes through the digestive system without raising blood sugar. Only net carbs affect insulin response and ketosis.

Bananas also contain resistant starch (especially when less ripe), which behaves more like fiber than sugar. A greener banana will have slightly lower net carbs and a lower glycemic impact than a very ripe one.

Frequently Asked Questions

A medium banana (118g) has 26.9g total carbs and 23.8g net carbs. A small banana (100g) has about 20.2g net carbs; a large banana (136g) has about 27.4g net carbs. Half a banana has 12.1g net carbs.

No. A medium banana has 23.8g net carbs — more than the typical strict keto daily limit of 20g. Even half a banana uses most of a day's keto budget. Berries are better low-carb fruit alternatives.

A medium banana (118g) contains 26.9g total carbs and 23.8g net carbs (26.9g minus 3.1g fiber), with 105 calories.

A medium banana has 105 calories. Half a banana has 53 calories. A large banana (136g) has about 121 calories. Per 100g, bananas have 89 calories.

Half a medium banana (about 60g) has 12.1g net carbs and 53 calories (13.7g total carbs minus 1.6g fiber).

A medium banana contains 14.4g of sugar (fructose and glucose). This natural sugar is responsible for both the sweet taste and the high glycemic impact. Per 100g, bananas have 12.2g of sugar.

A medium banana has 23.8g net carbs and 26.9g total carbs. How much carbs you get depends on size: a large banana (136g) has 27.4g net carbs, a half banana has about 12.1g net carbs, and per 100g a banana has 20.2g net carbs. All figures are USDA-verified.

A medium banana (118g) contains 26.9g of total carbohydrates, of which 3.1g is dietary fiber and 14.4g is natural sugar. Net carbohydrates (total carbohydrates minus fiber) equal 23.8g. Per 100g, bananas have 22.8g total carbohydrates and 20.2g net carbohydrates.

Nutrition data sourced from USDA FoodData Central. Values are for raw, fresh bananas.