A method for determining or predicting the adequacy parameters that will be achieved at the end of a kidney substitution treatment during said kidney substitution treatment wherein the kidney substitution treatment is provided by a machine, which has an extracorporeal blood system pumping the patient blood through the blood chamber of a dialyzer, wherein the dialyzing fluid collects the waste products from the patient after flowing through the dialyzing fluid chamber of the dialyzer and wherein a device able to measure a adequacy parameter is coupled with the kidney substitution treatment machine and wherein the slope of a preferable linear guideline for the adequacy parameter is compared to the slope of the delivered adequacy parameter and if the slope of both are equal a linearization is performed to determine or predict the adequacy parameter at the end of the kidney substitution treatment.
