Letter mail size

The size of a letter mail piece is typically measured in inches and is governed by the United States Postal Service (USPS) regulations. Here are the standard sizes for letter mail:

• Minimum size: 3.5 inches high x 6.125 inches long x 0.007 inch thick (89 mm x 156 mm x 0.18 mm)
• Maximum size: 6.125 inches high x 11.5 inches long x 0.25 inch thick (156 mm x 292 mm x 6.4 mm)

The USPS also has specific guidelines for the thickness of letter mail:

• Minimum thickness: 0.007 inch (0.18 mm)
• Maximum thickness: 0.25 inch (6.4 mm)

It's worth noting that these sizes are for standard letter mail, and there are other types of mail, such as large envelopes, flats, and packages, that have different size and weight requirements.

Here are some examples of common letter mail sizes:

• Standard #10 envelope: 4.125 inches high x 9.5 inches long x 0.007 inch thick (105 mm x 241 mm x 0.18 mm)
• A2 envelope: 4.375 inches high x 9.5 inches long x 0.007 inch thick (111 mm x 241 mm x 0.18 mm)
• A6 envelope: 4.5 inches high x 6.5 inches long x 0.007 inch thick (114 mm x 165 mm x 0.18 mm)

Keep in mind that these are general guidelines, and the USPS may have specific requirements for certain types of mail, such as certified mail or registered mail.