What is the best size for a postcard mailing?
• First Class or Presorted First Class mailings have a “Postcard size” postage rate but with very specific size limits. The piece must be no smaller than 5″ x 3.5″, and no larger than 6″ x 4.25″. • The maximum size for Presorted Standard Mail is 11.5″ x 6.125″. You will want to consider the aspect ratio before you make your final determination on size. • To obtain the lowest automation-compatible postage rates, your mailpiece must meet the USPS’s “Aspect Ratio” requirement; that is, the length to width ratio must fall between 1.3 and 2.5. You can determine this by dividing the length of your piece by the width. For example, a 8.5″ x 5.5″ postcard has an aspect ratio of 1.54 (8.5″ ÷ 5.5″), which falls in the acceptable range for the best automation discounts. • One more critical element: If the size of your postcard falls between 5″ x 3.5″ and 6″ x 4.25″, then your paper stock must be at least .007″ (seven thousandths) of an inch thick. Postcards larger than 6″ x 4.25″ must be .009″ (ni
