A least-squares parametric curve-fitting method is used to calibrate a circular dichrometer against a standardized spectropolarimeter. An application of this technique is demonstrated by determining the “calibrated” molar circular dichoic absorption, ϵ1-ϵr, of two camphor derivatives in solution. Maximal values of +2.20 for d-10-camphorsulfonic acid in water, + 1.54 for d-camphor in methanol, and +1.69 for dcamphor in dioxane are found at 291, 296, and 300 mμ, respectively. It is concluded that these values may be used as standards for calibration provided some precautions regarding solute and solvent purity are taken. © 1969, American Chemical Society. All rights reserved.