The utility is intended for calculation of precise values of solution concentration and volume resulting from mixing of two water solutions. Example: concentrations of initial C (in) and added C (add) solutions are 20 mM and 65 mM, correspondingly. One needs to prepare 2.5 ml of solution V (end) with final concentration C (end) equal to 35 mM. It is necessary to calculate volumes of initial V (in) and added V (add) solutions (for details see Help). The utility allows to calculate quantitative characteristics of a solution and a dry substance as a result of addition of the dry substance to a water solution. Example: it is necessary to calculate what amount of dry urea is necessary to add to 2 M urea solution C (in) to prepare 6 M solution C (end). The volume of initial solution V (in) is 100 ml (for details see Help).