Tachometer

Does onyone have a clue as to how to build a tachometer. I know to use the frequency to voltage converter chip, but once I get the voltage, what do i do with it to display RPM values on the Seven segment displays. I would greatly appreciate a helpful hint. My tachometer ranges from 1000 to 7000 RPMs. Thanks

Search the forum for tachometer, this has been asked many times before and there are a wide variety of solutions.