Official exchange rate is either 1.82 or 1.8204, depending on how many digits of accuracy are required. For most people, 1.82 is fine. For larger salaries ($500,000 plus), four digits of accuracy is recommended. For major items (a $100,000 bonus, a sale of a residence, etc.), a spot rate of the day can be found on
www.oanda.com. You need not use the spot rate except for extremely large one-off items.
IRS Circular 230 Disclosure: To ensure compliance with requirements imposed by the U.S. Internal Revenue Service, we inform you that any tax advice contained in this communication (including any attachments) was not intended or written to be used, and cannot be used, by any taxpayer for the purpose of (1) avoiding tax-related penalties under the U.S. Internal Revenue Code or (2) promoting, marketing or recommending to another party any tax-related matters addressed herein.