The conversion between different units of concentration depends on several factors. One must first consider the units they are originally converting from and the units they want to convert to. Common units of concentration include molarity (M), molality (m), percent by mass (%), and percent by volume (%v/v). Then, the appropriate converting factor must be used to get the correct result. For example, to convert from g/mL to M, the concentration must be multiplied by 10^3/Mw.