Are you wanting to apply to get an idea of what your EFC will be? If so, use an EFC Calculator. FinAid | Calculators | Expected Family Contribution (EFC) and Financial Aid
Do both the federal method and institutional. Many privates use the both methods. If there is a non-custodial parent, then their income (and step-parent incomes) might also be included at some schools.
BTW...an EFC is not the most you/your family will be expected to pay. Most schools do not meet need. Most schools "gap". So, even if a school costs - say - $28k per year for tuition, room, board and books, and your EFC is - say - $8000, that doesn't mean that you'll get $20k in aid.