The standard deduction is the minimum deduction. A simple calculator indeed should take this into account since it will affect everyone's tax liability. A rec

The standard deduction is the minimum deduction. A simple calculator indeed should take this into account since it will affect everyone's tax liability. A recent study showed only about 1/3 of tax returns used itemized deductions [1]. [1]: http://taxfoundation.org/article/most-americans-dont-itemize-their-tax-returns http://taxfoundation.org/article/most-americans-dont-itemize... edit: good point on the EITC as well. This also severely affects the bottom of the scale and you don't need to itemize to take advantage of it.