Letter Mailing

A "letter" can be an envelope package, a self-mailer folded brochure or even a card ... as long as it's within the minimum and maximum sizes shown below.

Do not exceed 6-1/8 x 11-1/2. Any larger takes the piece into flat category.
Minimum thickness .007 inch (if no more than 4-1/4" high and 6" long); .009 inch (if more than 4-1/4" high or 6" long or both). Maximum thickness .016 inch.



Calculate Postage on a Letter Size Mailing | Get A Quote on a Letter Size Mailing



A piece of First-Class mail weighing one ounce or less is non-standard if it exceeds any of the following size limits:

1. Its length exceeds 11-1/2 inches


2. Its height exceeds 6-1/8 inches


3. Its thickness exceeds 1/4 inch


4. Its aspect ratio (length divided by height) does not fall between 1 to 1.3 and 1 to 2.5 inclusive. For example, a piece measuring 4” long by 4” high would have an aspect ratio of 1, which would make it non-standard. A piece 8” long by 5” high would have an aspect ratio of 1.6, which would be standard.
   
   The nonmachinable surcharge For Letter Size Standard Mail will be $0.04 per piece
   
   The nonmachinable surcharge For Letter Size nonprofit Mail will be $0.02 per piece
   
   Nonmachinable Criteria
   A letter-size piece is nonmachinable if it has one or more of the following characteristics (see new DMM C010.1.1) for how to determine the length, height, top, bottom, and sides of a mailpiece):
   a. If the aspect ratio (length divided by height) is less than 1.3 or more than 2.5.
   b. If it is polybagged, polywrapped, or enclosed in any plastic material.
   c. If it has clasps, strings, buttons, or similar closure devices.
   d. If it contains items such as pens, pencils, or loose keys or coins that cause the thickness of the mailpiece to be uneven.
   e. If it is too rigid (does not bend easily when subjected to a transport belt tension of 40 pounds around an 11-inch diameter turn).
   f. If it is a mailpiece more than 4-1/4 inches high or 6 inches long and the thickness is less than 0.009 inch.
   
   
   Letter First-Class - 31.2 to 41 (1 oz. or less)
   
   Standard (Bulk) - Regular 17.7 to 52 (Limit 3.3 ounces or less)
   
   Nonprofit - 10.8 to 42.9 (Limit 3.3 ounces or less)
   
   Depending on presort qualifications and automation barcoding.
   
   (Ask your KD Mailing & Fulfillment specialist for exact rate)
   
   Click here to download Dimensional Standards Template in pdf format. You will need Adobe Acrobat Reader.
   
   Click here for free Adobe Acrobat Reader.