The vapor-phase Raman spectra of an atmosphere of cyclohexane vapor heated to 90 and 110 °C collected over a large period of time and utilizing a high laser power of 4W show hot band series starting at 380.8 cm-1 and corresponding to the v6(A1g) ring-inversion vibration. Fitting this data with a one-dimensional potential energy function allows the barrier to planarity of 8600 cm-1 (24.6 kcal/mol) to be calculated. Ab initio calculations (MP2/cc-pVTZ) predict a value of 10 377 cm-1 (29.7 kcal/mol), while DFT (B3LYP/cc-pVTZ) calculations predict 8804 cm-1 (25.2 kcal/mol).