According to IRS, gross income means all income you received in the form of money, goods, property, and services that is not exempt from tax, including any income from sources outside the United States or from the sale of your main home (even if you can exclude part or all of it).
Gross income is the starting point for determining Federal and state income tax.
If you need to figure out your income tax, you can refer to the federal tax tables and State tax tables
- Federal Iincome Withhold tables
http://www.halfpricesoft.com/federal_income_tax_2013.asp
http://www.halfpricesoft.com/state-tax-table-2013.asp