I like that it's easy to use, is extremely accurate (I get my numbers within 1%), very user friendly when using as an internal system for payroll processing or accounting purposes with small businesses - even if they have no employees yet! Honestly though? It doesn't really do any better than similar services out there in terms of accuracy so you might want try other free options first before committing fully into this one!! The best thing about these online calculators are their ease-of-use/quick results compared to more complex math formulas used by many companies now days which can take hours off work time.