So what is an EFC? Your Expected Family Contribution (EFC) is an index number that colleges use to determine how much financial aid you’re eligible to receive. Your EFC is calculated according to a formula established by law and the information from your Free Application for Federal Student Aid (FAFSA). The EFC factors in your family's taxed and untaxed income, assets, and benefits (such as unemployment or Social Security). Your family size and the number of family members who will attend college during the year are also considered. Note: Your EFC isn't the amount of money your family will have to pay for college and it isn't the amount of federal student aid you'll receive.