A number of experimental methods had been developed till date to evaluate and study the periodic properties. To study these periodic properties theoretically we have developed a new linear approach. A mathematical periodic function has been developed to calculate atomic radii (covalent and vander Waal) of any element by knowing just its atomic number. This function consists of a common equation along with additional terms (correction factor) for different blocks (s, p, d and f) of periodic table. This function has been derived mathematically by relating different factors in form of correction factors which affect the atomic radii using graphs. It takes into accounts the chemical behaviour of all the elements in their respective groups and periods.