For mail sent through the U.S. Postal Service, postcards must be at least 3.5 inches high by 5 inches long by 0.007 inch thick and no bigger than 4.5 inches high by 6 inches long by 0.016 inches thick. The standard-size ... More »

www.reference.com Business & Finance Mail & Shipping Postal Services

The average size of a standard postcard is 4 inches high by 6 inches wide. In the United States, a postcard of this size can be mailed under a special First-Class rate. More »

Most commercially-produced postcards measure approximately 4.21 inches by 5.47 inches. Less commonly, smaller postcards are typically 3.5 inches by 5.5 inches, close to the minimum size the USPS allows. More »

The differences in U.S. Postal Service shipping prices are due to the size of the package, the type of service the person is choosing and the distance to the mail's destination. The weight of the package also plays a rol... More »

The Global Forever stamp can be used to mail a postcard or 1-ounce letter-size letter anywhere in the world by First Class Mail International delivery, according to the U.S. Postal Service. In 2014, a Global Forever stam... More »

The average size of a standard postcard is 4 inches high by 6 inches wide. In the United States, a postcard of this size can be mailed under a special First-Class rate. More »

First-class mail is a type of mail often sent through the U.S. Postal Service. It includes postcards, letters, large envelopes and small packages that are under 13 ounces in weight. First-class mail is given the highest ... More »