What are the minimum dimensions for mailpieces?

What are the minimum dimensions for mailpieces?

• A. Three and a half inches in height, by five inches in length, and .007 inches thick.
• B. Two inches in height, four inches in length, and .005 inches thick.
• C. Four and a half inches in height, six inches in length, and .01 inches thick.
• D. Three inches in height, five inches in length, and .006 inches thick.

Answer: (A)

The main idea here is understanding the smallest size a mailpiece can be and still be treated as a standard piece by USPS. For letters, the smallest allowable dimensions are 3.5 inches in height, 5 inches in length, and a thickness of at least 0.007 inches. This set—3.5 by 5 by 0.007 inches—meets all three minimums exactly, so it is the smallest size USPS accepts.

The other options fail because they don’t hit all three minimums at once. One option is too short in height and length, another is also too short in height, and the remaining option is thicker than the minimum, so while it would still be a mailpiece, it isn’t the smallest possible size.