What is the standard size envelope for mailing

The standard size envelope for mailing in the United States is typically one of the following:

  1. Number 10 envelope: This is the most common size for standard business correspondence and is usually used for letters, bills, and other documents. It measures 4 1/8 inches wide, 9 1/2 inches long, and has a flap on the back that is 3/4 inch wide.
  2. Number 9 envelope: This size is slightly smaller than a Number 10 envelope and is often used for smaller documents, such as receipts, invoices, and notes. It measures 3 5/8 inches wide, 8 3/4 inches long, and has a flap on the back that is 1/2 inch wide.
  3. Number 6 3/4 envelope: This size is even smaller than a Number 9 envelope and is often used for very small documents, such as postcards, greeting cards, and small notes. It measures 3 1/2 inches wide, 6 1/2 inches long, and has a flap on the back that is 1/4 inch wide.

It's worth noting that these sizes are not set in stone, and some businesses or organizations may use different sizes or shapes for their envelopes. Additionally, some envelopes may be designed for specific purposes, such as overnight delivery or international mail, which may require special sizes or shapes.

Here are some general guidelines for the standard sizes of envelopes:

Keep in mind that these are general guidelines, and the specific size of an envelope may vary depending on the intended use and the preferences of the sender.