How many cups is a whole banana?

Quick Answer

A whole medium banana is approximately 1/2 cup in volume. This can vary slightly depending on the size of the banana. Generally, a medium 7-8 inch banana weighs about 4-5 ounces and fills about 1/2 cup when mashed.

Calculating Banana Volume

To calculate the volume of a banana in cups, you first need to know the size and weight of the banana. Bananas are categorized by size as follows:

  • Small/Extra Small: 5-6 inches long, about 3 ounces
  • Medium: 7-8 inches long, about 4-5 ounces
  • Large/Extra Large: 9 inches or longer, 5-6 ounces or more

A standard US cup measure holds 8 fluid ounces or 240 ml. So to convert the weight of a banana to cup volume, we need to estimate the density and do some math:

  • A small banana weighs around 3 ounces. 3 oz is about 0.375 cups.
  • A medium banana weighs around 4-5 oz. 4 oz is 0.5 cups. 5 oz is 0.625 cups.
  • A large banana weighs around 5-6 oz. 5 oz is 0.625 cups. 6 oz is 0.75 cups.

So a medium 7-8 inch banana weighing around 4-5 ounces will fill approximately 1/2 cup volume when mashed.

Actually Measuring Banana Volume

While the calculations above provide estimates, you can get a more accurate measure of banana volume by actually mashing it and measuring the cups.

Here is a step-by-step process:

  1. Peel the banana.
  2. Slice into several pieces and add to a bowl.
  3. Use a fork to mash the banana until relatively smooth.
  4. Scoop the mashed banana into a measuring cup.
  5. Level off the top and check the measurement. A medium 7-8 inch banana should yield about 1/2 cup.

When mashed, a banana’s texture and moisture content means it may not fill the cup precisely to the brim. Expect some variation from the 1/2 cup estimate based on the banana’s ripeness, moisture and exact size.

Factoring Ripeness into Banana Volume

A banana’s stage of ripeness can alter its volume measurement in cups when mashed.

  • An unripe green banana will mash into less volume as it contains less moisture.
  • A ripe yellow banana with a few brown spots will mash into the greatest volume.
  • An overripe brown banana may mash down into slightly less volume as some moisture has escaped.

So very ripe bananas may potentially exceed 1/2 cup volume by a tablespoon or two when mashed and measured, while an unripe banana may fall short of a 1/2 cup.

Volume When Sliced vs. Mashed

You’ll get different measurements if you calculate the volume of sliced bananas rather than mashed.

Sliced, a medium 7-8 inch banana may fill around 3/4 to 1 cup, since slicing gives you tidy, stackable banana rounds that pack together nicely.

Mashing eliminates all the air pockets and gaps, compressing a banana into the least space possible. So mashing always yields a smaller volume measurement compared to slicing.

Weight of a Cup of Mashed Bananas

If you wanted to reverse the calculation and determine the weight in ounces of 1 cup of mashed banana, here is an estimate:

  • 1 cup of mashed banana is approximately 5 ounces in weight.
  • 2 cups of mashed banana would be around 10 ounces.
  • 1/2 cup of mashed banana would be around 2.5 ounces.

This is based on a medium banana of around 4-5 ounces filling 1/2 cup when mashed. The weight-to-volume relationship stays proportional when you scale the quantity up or down.

So if you needed 2 cups of mashed bananas for a baking recipe, expect to use about 4 medium bananas totaling 10 ounces.

Banana Volume in Baking Recipes

In baking recipes like breads and muffins, mashed banana is often used as a substitute for ingredients like oil, butter or eggs to add moisture and bind ingredients together.

Knowing banana volumes and weights helps when adapting recipes:

  • In muffins, 1/4 cup oil can generally be replaced with 1/2 mashed banana.
  • In bread loaves, 1/3 cup oil can be replaced with about 2/3 cup mashed banana.
  • As a binder in pancakes or cookies, 1 egg can be substituted with about 1/2 cup mashed banana.

You may need to experiment slightly based on the ripeness of the bananas used. But this gives you a good starting point for replacing other wet ingredients with mashed banana in your baked goods.

Nutrition Information

Here are the basic nutrition facts for a medium 7-8 inch banana weighing about 4-5 ounces:

Nutrient Amount
Calories 105
Carbohydrates 27g
Sugar 14g
Fiber 3g
Fat 0.4g
Protein 1.3g
Vitamin C 9% DV
Manganese 14% DV
Potassium 9% DV

Bananas are a good source of potassium, vitamin B6, vitamin C, and fiber. Their carbohydrate and natural sugar content provides a quick source of energy.

Due to their carbohydrate content from starch and sugars, bananas have an estimated calorie density of 105 calories per a medium fruit.

Typical Uses for Measuring Bananas in Cups

Here are some of the most common reasons you may need to know banana volumes and weights in cups:

  • Baking – Using mashed bananas to replace oil, butter or eggs
  • Smoothies – Adding banana as a thickener and nutritional boost
  • Baby Food – Pureeing bananas and measuring portions
  • Yogurt Parfaits – Layering sliced bananas in measured amounts
  • Overnight Oats – Mixing in mashed banana as a sweetener
  • Ice Cream – Blending frozen bananas into “nice cream”
  • Chia Pudding – Folding in sliced bananas for texture

In most cases, the banana is being used to add moisture, binding, sweetness and flavor to dishes rather than for precise nutritional needs. So the volume measures do not need to be extremely precise.

Still, having a good estimate of banana volumes can help when adapting recipes and creating balanced nutrition.

Serving Size Comparisons

To put the 1/2 cup volume of a medium banana into perspective, here’s how it compares to some other common serving sizes of fruits:

Fruit Serving Size
Banana 1 medium (1/2 cup)
Apple 1 small (1 cup sliced)
Blueberries 1 cup
Strawberries About 8 medium berries (1 cup)
Grapes About 32 grapes (1 cup)
Orange 1 medium (1 cup sections)

A medium whole banana is considered one standard fruit serving. Measuring about 1/2 cup mashed, it contains a similar quantity to 1 cup of berries or sliced fruits.

This comparison helps give some context for substituting banana for other fruits in recipes or eating it as part of a balanced diet.

Tips for Measuring Bananas

To get accurate volume measurements when using bananas:

  • Select ripe bananas for maximum volume – ripe bananas mash down into more cups than unripe.
  • Mash thoroughly and evenly for most precision.
  • Use a dry measuring cup and level off the top surface.
  • Avoid over-packing the cups which can throw off the measurement.
  • Weigh for a more precise measurement than volume in cups.


A medium 7-8 inch banana weighs about 4-5 ounces and fills approximately 1/2 cup volume when mashed.

This conversion can vary slightly based on ripeness and exact banana size. But provides a helpful standard estimate for recipes and nutrition tracking.

Knowing volumes of bananas can help when baking, blending smoothies, or making purees and puddings. Comparing it to volumes of other fruits also gives context for serving sizes.

So while not a precise science, estimating banana quantities in cups can be useful for many kitchen needs. When cooking, be prepared to adjust as needed based on variations in banana ripeness and moisture content.

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