As of 2014, the domestic postage price in the United States for a large letter is 49 cents. This price applies to all envelopes that weigh less than 13 ounces and do not exceed 11 1/2 inches long or 6 1/8 inches wide.
Letters traveling to international destinations need additional postage. Larger letters and small packages can be sent with postage ranging from less than $1 to more than $20. International postage rates also vary based on the destination of the letter. In some cases, letters need to be sent via a premium service, such as Priority or Express mail. For exact rates, check the letter's size and weight dimensions and look up the information on the official USPS website.