The fundamental IR vibrational modes of CHF2OCF3 (E125), CHF2OCHF2 (E134), and CH3OCF3 (E143a) have been examined by ab initio molecular orbital calculations and have been compared with FT-IR measurements. A complete assignment of all fundamental vibrational modes has been made for each fluorinated ether. As a calibration for the fluorinated ethers, the fundamental IR vibrational modes of dimethyl ether have been reexamined by ab initio methods and have been compared with literature assignments.