Most of the speedometers are mechanical devices and analog in nature. They are normally used to indicate the speed of the rotating mechanical part such as the speed of a car or other machineries whose their speed is regularly observed in order to maintain its peerformance. A common speedometer is simply a pointeer with back-ground scale, so that the exact speed is difficult to deteermine accurately. The digital speedometer will accurately display the speeed in numerical form on the seven-segment display. This project shows a complete construction of a digital speedometer that can be installed in a car. Although this unit is available commercially, the purpose of this project is to understand and identify the theory and practice behind as well as the design in its application.