# Treas. Reg. § 1.989(b)-1: Definition of weighted average exchange rate.

Source: eCFR as of 2026-10-19 <https://www.ecfr.gov/current/title-26/section-1.989(b)-1>. Interprets 26 U.S.C. § 989.

For purposes of section 989(b)(3) and (4), the term “weighted average exchange rate” means the simple average of the daily exchange rates (determined by reference to a qualified source of exchange rates described in § 1.988-1(d)(1)), excluding weekends, holidays and any other nonbusiness days for the taxable year. 

[T.D. 8263, 54 FR 38664, Sept. 20, 1989. Redesignated by T.D. 8367, 56 FR 48437, Sept. 25, 1991; 57 FR 6060, Feb. 18, 1992; T.D. 9452, 74 FR 27890, June 11, 2009]