A method is presented for executing the Kramers-Kronig transforms of electrochemical impedance data on a computer. Attention is paid to the extrapolation techniques for impedance data with a limited frequency range. It is shown that impedance spectra of systems with blocking electrodes, exhibiting a CPE-type response, are also Kramers-Kronig transformable. The necessity and limitations of these transforms with respect to impedance data are briefly discussed.