USPS Priority Medium Flat Rate Box
Top Loading box
Outside: 11 1/4″ x 8 3/4″ x 6″
Inside: 11″ x 8 1/2″ x 5 1/2″
or
Side loading box
Outside: 14″ x 12″ x 3 1/2″
Inside: 13 5/8″ x 11 7/8″ x 3 3/8″
$18.40Price
Excluding Sales Tax
Top Loading box
Outside: 11 1/4″ x 8 3/4″ x 6″
Inside: 11″ x 8 1/2″ x 5 1/2″
or
Side loading box
Outside: 14″ x 12″ x 3 1/2″
Inside: 13 5/8″ x 11 7/8″ x 3 3/8″