A Monte Carlo simulation, coupled with bead-model hydrodynamic calculation, has been employed to predict hydrodynamic coefficients and other solution properties, of wormlike macromolecules, covering the full range of the wormlike model, from short cylinders to very long, fully flexible chains, eventually including excluded-volume effects. The results have been implemented in a computational tool, Multi-HYDFIT, which performs the determination of the structural parameters from a set of experimental data of various properties for multiple samples with varying molecular weight. An analysis of experimental data of double-stranded DNA demonstrates that the Multi-HYDFIT treatment, with our simulation results, predicts the various solution properties of DNA in an extremely-wide range of sizes, from 8 to 200 000 base pairs, yielding values of the parameters that agree with those of the double helix. The scheme is also applied to other synthetic and biological macromolecules, like the very stiff, triple-helical schizophyllan polysaccharide or the very flexible poly(isobutylene) polymer, the latter covering again an extremely wide range that includes quite short oligomers.