A method, including performing an initial ablationof a tissue using an electrode in a probe distal end toapply a first power to the tissue, and measuring a changeof temperature of the distal end while applying the firstpower. The method also includes estimating a thickness ofthe tissue in response to the measured change oftemperature, and in response to the estimated thickness,computing at least one of a second power required and atime period for ablation, to complete ablation of thetissue. The method further includes performing asubsequent ablation of the tissue using the computed atleast one of the second power and the time period forablation.
