Today, most families require some financial assistance to pay for college. Published tuition, fee, room and board charges average $14,333 a year at four-year public colleges (for in-state residents) and $34,132 at private colleges, according to the College Board. So how do you know if you are eligible for aid? The only way to be sure is to submit the Free Application for Federal Student Aid (FAFSA) which is required by all colleges to be considered for federal financial aid, and in most cases – institutional aid. Every school uses the same formula to determine how much financial aid to award to students.

COA
The school's COA includes tuition, fees, room and board, books and school supplies, travel costs, and personal and incidental expenses.
EFC
Your EFC is the amount your family is estimated to be able to contribute toward college costs each year. EFC is a commonly used financial aid term, which indicates both a student's and a parent's current ability to pay. The federal government uses a formula, sometimes referred to the Federal Methodology, to assess your family’s financial circumstances, and will come up with the EFC. Many factors affect EFC, including parent’s previous year income and assets, student’s previous year income and assets, age of older parents, number of children in college, number of persons in household, etc. Each factor has a different weight. Both parents and students are expected to contribute to educational costs.
The below chart demonstrates how your financial need differs at colleges of different costs, yet your EFC remains constant.

Schools do not always have enough funds to meet 100% of your financial need. When need is not fully met, there is said to be a gap or unmet need.