Postal Information

Postcard Letter
Rectangular cardstock mail piece
not contained in an envelope
Small rectangular mail piece
no thicker than 1/4 inch
Flat (Large Envelope) Parcel (Package)
Flat rectangular mail piece no thicker
than 3/4 inch
A three–dimensional mail piece contained
in a box‚ thick envelope or tube‚ weighing
up to 70 pounds
Mail Piece Dimensions
Shape Length Height
Postcard 5 inch min.
6 inch max.
3-1/2 inch min.
4-1/4 inch max.
Letter 5 inch min.
11-1/2 inch max.
3-1/2 inch min.
6-1/8 inch max.
Flat 11-1/2 inch min. 6-1/8 inch min.
Parcel Weight cannot exceed 70 pounds. Length + girth (distance around the
thickest part of the package) cannot exceed 130 inches.
Letters: maximum thickness 1/4 inch.
Flat: maximum thickness 3/4 inch.

Once a piece of mail exceeds the maximum length‚ height‚ or thickness of one shape‚ it automatically gets classified as the next largest shape.

For shipping weight and size please click here: postalcalc.gov