Dimensions

Letters

Letter Dimensions

  Minimum   Maximum
Length   5 inches   11-1/2 inches
Height   3-1/2 inches   6-1/8 inches
Thickness   0.007 inch   1/4 inch

Aspect Ratio: length divided by height must be more than 1.3 and less than 2.5“.
Non-machinable letter-size pieces and pieces over 3.3 ounces are subject to flat-size rates.

Aspect Ratio: length divided by height must be more than 1.3″ and less than 2.5″.


 

Flats

Flats Dimensions

 Minimum  Maximum
Length   11-1/2 inches   15 inches
Height   6-1/8 inches   12 inches
Thickness   1/4 inch   3/4 inch

Flats exceeding these dimensions, rigid flats, and flats with certain characteristics are subject to parcel rates.

 


 

Postcards

Postcard Dimensions

 Minimum  Maximum
Length   5 inches   6 inches
Height   3-1/2 inches   4-1/4 inches
Thickness   .007 inch   .016 inch

Aspect Ratio: length divided by height must be more than 1.3″ and less than 2.5″.