How Many Calories Is a Banana? By Size and Ripeness

Calories in a banana depend on its size, and a medium one (118 g) has about 105 kcal. A small one has 90 kcal and a large one 121 kcal, and the count drops as the fruit gets very ripe. The rest of this page shows where each number comes from.

How many calories is a banana of each size?

A banana has about 89 kcal per 100 g, so size matters more than anything else. USDA’s SR Legacy record for raw bananas lists a weight for each size. I multiplied each weight by 0.89 kcal per gram, so every row below comes from the same record.

Size	Length	Weight (g)	Energy (kcal)
Extra small	under 6 in	81	72
Small	6 to 6-7/8 in	101	90
Medium	7 to 7-7/8 in	118	105
Large	8 to 8-7/8 in	136	121
Extra large	9 in or longer	152	135
Label serving (NLEA)		126	112

From the smallest to the largest is a gap of 63 kcal. The realistic slip is calling a large one “medium”.

The lengths are the record’s own size bands. Hold a banana against a ruler once and you will know which row you usually buy.

Does ripeness change the calories in a banana?

Yes, a little: very ripe fruit has fewer calories per gram than ripe fruit. USDA’s Foundation Foods database has two records. Ripe and slightly ripe bananas have 88 kcal per 100 g, and overripe bananas have 77 kcal. Both use the specific Atwater energy factors, and both weigh the fruit peeled.

Record	Peeled banana (g)	Per 100 g (kcal)	Per banana (kcal)
Ripe and slightly ripe	115	88	101
Overripe	110	77	85

The sums are 88 kcal × 1.15 = 101 kcal and 77 kcal × 1.10 = 85 kcal. The overripe fruit comes out 16 kcal lighter. Small. Carbohydrate falls from 23 g to 20.1 g per 100 g between the two records, which looks like where most of the gap comes from.

I wouldn’t build a plan around 16 kcal. A gap that repeats every day is another matter, and how many calories is a pound shows what it turns into on the scale. Each record is a set of samples, not a rule for every banana in your fruit bowl. If you want one number, use the ripe one and accept that a very spotty banana may run a little lower.

The 101 kcal here and the 105 kcal in the size table come from two different records: SR Legacy dates from 2018, and the Foundation records are newer. Pick one and stay with it for a month, because a diary that swaps records moves with the data instead of with what you eat.

How many calories are in 100 grams, a cup or half a banana?

In 100 g of banana there are 89 kcal, or 88 kcal by the newer record. Other measures follow from the same weights in the record.

Measure	Weight (g)	Energy (kcal)
100 g	100	89
Half a medium banana	59	53
1 cup, sliced	150	134
1 cup, mashed	225	200

A mashed cup is about two medium bananas, while a sliced cup is only a little over one, 134 kcal against 105, so a smoothie recipe that lists fruit by the cup needs a second look. Baking is worse. A recipe that asks for “1 cup mashed” has just put 200 kcal into the batch, and the oil in the same recipe is easier to miss, as the calories in a tablespoon of olive oil show. To turn the whole batch into a number per slice, use the weigh-raw method in a recipe calorie counter.

How does a banana compare with other fruit?

Per gram, a banana is the densest fruit in the table, and per piece it sits close to an apple. I took one SR Legacy record for each fruit and the medium or label serving weight it lists. The apple is raw with skin, the orange is the all-varieties record, the grapes are red or green European type, and the strawberries are raw.

Fruit	Per 100 g (kcal)	Piece or serving	Weight (g)	Energy (kcal)
Banana, medium	89	1 banana	118	105
Apple, medium	52	1 apple	182	95
Grapes	69	1 label serving	126	87
Orange	47	1 fruit	131	62
Strawberries	32	1 label serving	147	47

A banana weighs less than an apple but carries more energy per gram, so the two land 10 kcal apart. Weigh your fruit. A heavy apple and a light banana can swap places.

How do I count a banana without guessing?

Weigh it peeled, then multiply. The peel isn’t part of the numbers above, and a banana weighed in its skin reads too heavy. A kitchen scale takes seconds, and one weigh-in tells you what your usual banana weighs, which is worth more than any chart, mine included.

I peel the banana onto the scale and read the grams. Then I multiply by 88 kcal per 100 g, which makes a peeled 120 g banana 106 kcal. In a rush, call it 100 kcal. If you eat half and leave the rest on the counter, weigh the half you ate, because the scale beats a guess in either direction. Eggs have the same problem, with size and cooking moving the count; calories per egg lays it out.

A medium banana also has about 14 g of sugars, 27 g of carbohydrate and 3.1 g of fiber, by the SR Legacy record. If you manage diabetes, how fruit fits your carbohydrate plan is something to settle with your care team, not a calorie table.

Calsa takes a line like “banana 120 g”. Each entry shows its source and the math, “per 100 g × grams”, so you can see where the number came from.