how much is the first class postage
The post office weighs packages by the ounce. 3. Calculate your postage rate using the international postage price calculator. For a first-class letter to Canada, the first ounce of postage costs 85 cents, a two-ounce letter costs $1.17 and a three-ounce letter costs $1.49, as of the time of publication. A Priority Mail International Flat Rate envelope costs $12.95 for any weight up to four pounds, with an expected delivery in six to 10 business days.