The coherent to Compton scattering cross-section ratio of calcium was measured experimentally for several polar scattering angles (90 • , 100 • , 110 • , 120 • , and 130 •) and azimuthal scattering angles (30 • , 20 • , 10 • , 0 • , − 10 • , and − 20 •). A high purity germanium semiconductor detector with a resolution of 199.6 eV at 5.9 keV was used. The theoretical values of the coherent to Compton scattering differential cross-section of calcium were calculated on the basis of nonrelativistic form factors, relativistic form factors, and S-matrix theories. It was observed that the experimental results were most compatible with the nonrelativistic form factor theory.