Question: how many forever stamps to mail a letter to europe?
Answer: If you use "Forever" stamps, those are worth $0.47 each, so you'd need 2 of those and another 21¢ in postage, or the Post Office sells "International Forever" stamps for $1.15 (valid for one ounce). Also: The $1.15 is the base international postage for a 1 oz.