Sizes & Rates

When you think of a letter, what comes to mind? A standard No. 10 envelope? Most likely the answer is yes. This is a popular size. However, since the “letter” in the bulk mail world covers a variety of sizes, you may decide to create a unique mail piece with its own special envelope. Please keep in mind the following size requirements for letters:
• Be Rectangluar
• Have dimensions greater than 3-1/2 inches high x 5 inches long x 0.007 inch thick
• Be no more than 6-1/2 inches high x 11-1/2 inches long x 1/4 inch thick
• The aspect ratio (length divided by height) must be at least 1.3 but no more than 2.5

The Postal Service uses the word “flats” to refer to large envelopes, newsletters, and magazines. Here again you may want to create something unique to draw attention to your piece. These are the requirements for flats:

• Have one dimension that is greater than 6-1/8 inches high x 11-1/2 inches long x ¼ thick
• Be no more than 12 inches high x 15 inches long x ¾ inch thick



 For more information please see the USPS website.