A method of setting a control or regulating device of a blood treatment apparatus for an upcoming blood treatment session, the blood treatment apparatus comprising: - a blood pump , connectable to an extracorporeal blood circuit for conveying blood through the extracorporeal blood circuit ; - a dialysis liquid inlet line ; - a dialysis liquid pump for conveying dialysis liquid through the dialysis liquid inlet line and/or an ultrafiltration pump and/or an effluent pump; - an input device for the user for entering flow values (Q B , Q dia , Q UF ) to be achieved or effected during an upcoming blood treatment session, by means of the blood pump and/or the dialysis liquid pump and/or the ultrafiltration pump and/or the effluent pump, and/or for entering a treatment target (d targ ) to be achieved by completion of the upcoming blood treatment session; - a reading device for reading and/or storing the flow values (Q B , Q dia , Q UF ) entered by the user and/or the treatment target (d targ ) entered by the user; - a control or regulating device , configured for controlling or regulating the blood treatment apparatus after the start of the upcoming blood treatment session based on flow values (Q B , Q dia , Q UF ) and/or treatment targets (d targ ) ; - a storage device , in which a correction factor (f korr ) is stored as a constant; wherein the method encompasses the following steps: a) providing, determining or reading out the correction factor (f korr ) from or out of the storage device ; b) correcting flow values (Q B , Q dia , Q UF ) entered by the user and/or the treatment target (d targ ) entered by the user by the correction factor (f korr ). - a blood pump , connectable to an extracorporeal blood circuit for conveying blood through the extracorporeal blood circuit ; - a dialysis liquid inlet line ; - a dialysis liquid pump for conveying dialysis liquid through the dialysis liquid inlet line and/or an ultrafiltration pump and/or an effluent pump; - an input device for the user for entering flow values (Q B , Q dia , Q UF ) to be achieved or effected during an upcoming blood treatment session, by means of the blood pump and/or the dialysis liquid pump and/or the ultrafiltration pump and/or the effluent pump, and/or for entering a treatment target (d targ ) to be achieved by completion of the upcoming blood treatment session; - a reading device for reading and/or storing the flow values (Q B , Q dia , Q UF ) entered by the user and/or the treatment target (d targ ) entered by the user; - a control or regulating device , configured for controlling or regulating the blood treatment apparatus after the start of the upcoming blood treatment session based on flow values (Q B , Q dia , Q UF ) and/or treatment targets (d targ ) ; - a storage device , in which a correction factor (f korr ) is stored as a constant; wherein the method encompasses the following steps: a) providing, determining or reading out the correction factor (f korr ) from or out of the storage device ; b) correcting flow values (Q B , Q dia , Q UF ) entered by the user and/or the treatment target (d targ ) entered by the user by the correction factor (f korr ). a) providing, determining or reading out the correction factor (f korr ) from or out of the storage device ; b) correcting flow values (Q B , Q dia , Q UF ) entered by the user and/or the treatment target (d targ ) entered by the user by the correction factor (f korr ). <EOS>