Measurements of solar radiation are ordinarily made on horizontal planes recording global, diffuse and reflected components. The beam component and distribution of the global radiation on tilted planes can be calculated via the said components, as the position of the Sun in the sky’s sphere is known. Another ordinary procedure is measuring beam and diffuse components and calculating global radiation. These measurements require stationary equipment and in such a way it is difficult to study the influence of different grounds on the distribution of radiation on the inclined surfaces due to the ground. This distribution has some importance in civil engineering, but it is not popular in the field of solar radiation investigations. Present paper shows how this distribution can be calculated measuring only global irradiance on the horizontal and vertical planes. Such an approach, which is valid in clear-sky and overcast conditions, allows the use of a portable measuring device and studies of different grounds. The coincidence of the calculated values with the actual is good, except for snow-cover and discrete cloud, which do not correspond to the isotropic sky and ground models.