How tons 37 cent stamps does it nick to dispatch a post card to Poland from the western US?

Answers:
Three, but you rubbish 21 cents

Yep, it's 90 cents, so you'll stipulation three of 'em.

Go to USPS.com and find total postage afterwards international and the two and from countries, the size of the item and it will you the postage.

Ninety cents from USA that would be three stamps.

http://ircalc.usps.gov/intlmailservices.