In recent years, X-rays with different radiological devices have been frequently used. X-rays are produced in vacuum tubes by bombarding a metal target with high-speed electrons whereas radiological images occur after the resulting radiation passes through the patient's body onto a photographic plate or a digital recorder to produce a radiological image. In radiology, devices that use X-rays can be classified as radiography, fluoroscopy, mammography and CT. In this study, we present a general approach for the simulation of X-ray spectra emitted from targets bombarded with electron beams for different energy ranges which are widely used in different radiological devices. The electron and photon transport is simulated by using the SpekCalc GUI code (version 1.1). In this study, we calculated the total photon spectra of the Tungsten (W) target for 150 keV and 12(c) anode angle and certain energies for required energy values which are necessary for a successful radiodiagnostic process. We also performed simulations with the same parameters by adding the filter material into the X-ray tube. We achieved a good agreement between the clinical data and the computational method. The results showed that the computational method is in accordance with the manufacturer parameters.