Abstract: A method and user interface are provided for independently and conveniently scaling y-values of multiple data sets whereby the data sets may be plotted against a common y-axis and provide satisfactory variability. A multiplier is selected by which data points in a data set are multiplied, allowing plots of multiple data sets to be graphed against a common range of y-axis values. The initial multiplier may be calculated and selected automatically by the computer on which the graphing is performed or may be manually selected by a user. If the results of the graphing are not satisfactory to the user, the user may change the multiplier for any data set. A spin button may be provided to enable the user to easily increment or decrement a multiplier in predefined steps, such as by factors of 10. Additionally, a computer-generated indicator may be displayed to assist the user in selecting a different multiplier.