How many calories are in a banana?

A banana's calories depend on its size, so the quickest way to an exact figure is to weigh it.

Peeled banana has 81 calories (kcal) per 100g, and about 1g of protein.¹ These figures, and every other one on this page, come from the UK government's food composition data.

How many calories are in one banana?

A peeled banana that weighs 120g has 97 calories.¹

To work out yours, weigh it and:

• Multiply by 0.81 if you weighed it peeled.

• Multiply by 0.51 if you weighed it whole, in its skin.

The whole figure is lower because the skin adds weight you don't eat. In the UK data, the flesh is just under two thirds of a whole banana's weight.¹

Where do a banana's calories come from?

Mostly from carbohydrate. Per 100g, a banana has 20g, of which 18g is sugars and 2g is starch.¹

There's almost no fat. For how the main nutrients fit together, see our guide to macronutrients and micronutrients.

How much protein is in a banana?

Very little. There's about 1g of protein in 100g of banana, and even a 160g banana has under 2g.¹

Protein supplies only a small share of a banana's calories. That's too little for UK rules to call a banana a source of protein.²

How does a banana compare with other fruit?

Of the six fruits below, banana has the most calories, protein, and carbohydrate per 100g.¹

Is a banana a source of potassium?

Yes. Peeled banana has 330mg per 100g, enough for UK rules to call it a source of potassium.^1,2,3

Potassium contributes to normal muscle function.² Eat bananas as part of a varied, balanced diet and a healthy lifestyle.

Banana calorie FAQs

How many calories are in 100g of banana?

Peeled, 81. Weighed whole, in its skin, 51.¹

Does a banana have more calories than an apple?

Yes, per 100g: 81 calories for peeled banana against 51 for apple eaten with the skin.¹

How much sugar is in a banana?

There are 18g of sugars in 100g of peeled banana, so 120g of it has about 22g.¹

The numan take

Weigh your banana, peeled or whole, and use the matching figure: 81 calories per 100g peeled, or 51 whole. A banana brings carbohydrate and potassium, but little protein. If you want protein alongside it, pair it with yoghurt or a glass of milk.

For a calmer way to log what you eat, see our guide to counting calories without becoming obsessive.

References

1. Public Health England. McCance and Widdowson's The Composition of Foods Integrated Dataset 2021. Public Health England, 19 March 2021. Food codes 14-318 (bananas, flesh only), 14-347 (bananas, raw, flesh only, weighed with skin; edible proportion 0.63), 14-350, 14-319, 14-321, 14-325, and 14-327. Fibre is AOAC fibre. Banana values from Department of Health, Nutrient analysis of fruit and vegetables, 2013 (11 samples). https://www.gov.uk/government/publications/composition-of-foods-integrated-dataset-cofid (opened 9 Nov 2026)

2. Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. Health claims, row "Potassium contributes to normal muscle function"; nutrition claims, rows "Source of protein" (at least 12% of energy from protein) and "Source of [name of vitamin/s] and/or [name of mineral/s]". Spreadsheet of 19 May 2026. https://www.gov.uk/government/publications/great-britain-nutrition-and-health-claims-nhc-register (opened 9 Nov 2026)

3. Regulation (EU) No 1169/2011 on the provision of food information to consumers, as it applies in Great Britain, Annex XIII Part A: nutrient reference value for potassium 2,000mg; a significant amount is 15% of the reference value per 100g. https://www.legislation.gov.uk/eur/2011/1169/annex/XIII (opened 9 Nov 2026)