Both liquid and dry measurement cups hold equal volume technically. However, they are designed differently to hold different types of ingredients conveniently. If you are holding a liquid in a dry cup and filling it up to the brim, then chances are you will spill some of it before it goes into the recipe. Liquid cups, on the other hand, have to measure lines a little below the brim. It protects the liquid from falling off and hence, offers an accurate measurement. Moreover, dry cups generally come up to 1 cup, whereas liquid cups come in a set that can measure up to 8 cups. So, if you are using a dry cup for liquid, it might take a lot of time.