How many stamps do you need to mail a letter from PA to CA?

Answer 1

One. Just like mailing a letter from one town in PA to the next one over. In the US, it costs the same to mail a letter from Savannah, GA to Rincon, GA as it does to mail a letter from Buffalo, NY to Honolulu, HI. The only possible difference is if this is a think heavy letter that would normally require a little extra postage. So you might go up from the normal $0.42 to $0.65. You never know until you get your letter weighed at the post office. If it is just a regular letter, put on one regular $0.42 stamp and send it on...