RVal is a program for Electronic Engineers and hobbyists. It will find the nearest preferred resistor values satisfying certain criteria or all within a given tolerance, in whichever range of preferred values the user selects. All the standard value ranges are supported; they are E6, E12, E24, E48 and E96. Preferred values can be selected according to the following criteria: The nearest preferred value to that specified. The pair of preferred values having the closest approximation to the required Ratio. Pairs of preferred values which, when placed in series or parallel provide the closest approximation to the required value. RVal also includes the facility to output a list of the values in the selected range.