How many stamps for 2.2 oz postage?

The number of stamps needed for 2.2 oz postage depends on the weight and the type of stamps you are using. For standard First-Class Mail in the U.S., a letter weighing up to 1 oz requires one stamp, and each additional ounce typically requires an extra stamp or additional postage. Therefore, for a 2.2 oz letter, you would generally need two stamps, potentially adding more if they are lower denomination stamps. It's best to check the current postage rates for the most accurate calculation.