A medium banana has about 105 calories ; most people can safely think of “around 100 calories” per banana as a good everyday estimate.

Quick Scoop

  • Extra small banana (under 6 inches): about 72 calories.
  • Small banana (6–7 inches): about 80–90 calories (often rounded to 90).
  • Medium banana (7–8 inches): about 105 calories.
  • Large banana (8–9 inches): about 121 calories.
  • Extra large banana (over 9 inches): about 135 calories.

Most of those calories come from carbs, with only small amounts from protein and fat, which is why bananas work well as a quick energy snack.

If you’re not sure about size, assuming “~100 calories per banana” is a practical rule of thumb for tracking.

HTML size table

html

<table>
  <thead>
    <tr>
      <th>Banana size</th>
      <th>Approx. length</th>
      <th>Approx. calories</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Extra small</td>
      <td>&lt; 6 inches</td>
      <td>~72 kcal</td>
    </tr>
    <tr>
      <td>Small</td>
      <td>6–7 inches</td>
      <td>~80–90 kcal</td>
    </tr>
    <tr>
      <td>Medium</td>
      <td>7–8 inches</td>
      <td>~105 kcal</td>
    </tr>
    <tr>
      <td>Large</td>
      <td>8–9 inches</td>
      <td>~121 kcal</td>
    </tr>
    <tr>
      <td>Extra large</td>
      <td>&gt; 9 inches</td>
      <td>~135 kcal</td>
    </tr>
  </tbody>
</table>

TL;DR: One banana is usually around 100 calories, give or take a bit depending on size.

Information gathered from public forums or data available on the internet and portrayed here.