Passport photos are typically 2 x 2 inches in size, which is about 51 x 51 mm and must be a perfect square.

Standard passport photo size

  • Common printed size: 2 x 2 inches (about 5.1 x 5.1 cm).
  • Shape: Square (equal width and height).
  • Often used for: U.S. passports, many U.S. visas, and other American ID photos.

Digital size and head area

  • Typical digital size: at least 600 x 600 pixels.
  • Head height: roughly 1 to 1 3/8 inches (25–35 mm) from chin to top of head, so the face fills a bit over half the photo.

Quick HTML table

html

<table>
  <thead>
    <tr>
      <th>Type</th>
      <th>Dimension</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Printed size</td>
      <td>2 x 2 inches (51 x 51 mm)</td>
    </tr>
    <tr>
      <td>Shape</td>
      <td>Square (1:1 aspect ratio)</td>
    </tr>
    <tr>
      <td>Typical digital size</td>
      <td>≥ 600 x 600 pixels</td>
    </tr>
    <tr>
      <td>Head height</td>
      <td>1 to 1⅜ inches (25–35 mm)</td>
    </tr>
  </tbody>
</table>

Note: Some countries use different sizes (like 35 x 45 mm), so always check the specific passport authority’s current rules before printing or uploading.

TL;DR: For “how big are passport photos,” the most common standard is a 2 x 2 inch, square photo with the head centered and taking up just over half the height.

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