A peritoneal dialysis device displays on a graphical interface a plurality of parameters and any values currently assigned to the parameters, and in response to a user selecting one of the displayed parameters, allows the user to input a value to be assigned to one of the parameters. A value is set for a number of fills parameter or a dwell time parameter based on the value received from the user. Parameter values are set in a peritoneal dialysis device by receiving from a user a selection of a therapy type, receiving from a user values for a plurality of parameters, calculating a value for a plurality of additional parameters based on the values received from the user, determining whether values for one or more of the plurality of parameters or one or more of the additional parameters do not meet one or more criteria, and, if necessary, updating one or more of the values received from the user so that all of the values for the plurality of parameters and the additional parameters meet all the criteria.