High schoolers are usually between about 14 and 18 years old in the United States, depending on their grade and birthday.

Typical ages by grade (U.S.)

  • 9th grade (freshman): usually 14–15 years old.
  • 10th grade (sophomore): usually 15–16 years old.
  • 11th grade (junior): usually 16–17 years old.
  • 12th grade (senior): usually 17–18 years old.

So when people ask “how old are high schoolers,” they’re generally talking about teens in that 14–18 range, with a few being a bit younger or older if they skipped or repeated a grade.

Quick HTML table

Since you asked for tables as HTML, here’s a simple one you can reuse:

html

<table>
  <thead>
    <tr>
      <th>Grade</th>
      <th>Common name</th>
      <th>Typical age range (U.S.)</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>9th</td>
      <td>Freshman</td>
      <td>14–15</td>
    </tr>
    <tr>
      <td>10th</td>
      <td>Sophomore</td>
      <td>15–16</td>
    </tr>
    <tr>
      <td>11th</td>
      <td>Junior</td>
      <td>16–17</td>
    </tr>
    <tr>
      <td>12th</td>
      <td>Senior</td>
      <td>17–18</td>
    </tr>
  </tbody>
</table>

Note: Other countries define “high school” and cut‑off dates differently, so ages can shift slightly, but a 14–18 range is still a good general guide for most systems that use four high school grades.

TL;DR: High schoolers are typically teens from about 14 to 18 years old, with the youngest in 9th grade and the oldest in 12th grade.

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