Your Expected Family Contribution, or EFC, is the amount of money you and/or your family are expected to pay for your college education per year. The U.S. Department of Education, using the financial information submitted on your FAFSA, runs the numbers though a complicated formula and determines the "official" amount of money you can afford to pay for college. The formula they use is publicly available, and it is not negotiable. 

Each college will calculate your Cost of Attendance, or COA. That's tuition, fees, books, housing, transportation, and other costs of living. The COA can be slightly different for each student. So that's the basic math of paying for college: each school determines your COA, and they deduct your EFC. What's left over is your need--how much you need in financial aid to be able to afford to attend their school.

Here are some things to think about:

Every school's determination of your Need will be different. They all have different COA, and many will also tweak your EFC. While your EFC is the official number from the government financial aid office, schools can adjust it—or even ignore it and do their own calculations. This is why more and more universities are asking for the more-detailed CSS profile.

Just because a school acknowledges your need doesn't necessarily mean they will cover your need. You can look up the average percentage of need met for any college, and it’s rarely 100%

Student loans are almost always a part of financial aid. Schools can claim they met your full need by offering you loans. If you can't afford to pay the full cost up front in cash--and most people can't--then you should expect that loans will be part of your financial aid package

While admissions decisions are very personal—for students and colleges—financial aid is strictly business. They may care that you can't actually meet the EFC, but they may not have enough money to do anything about it. Likewise, your sad or frustrating story may not be as big a factor as you might hope. Every year you hear stories about a parent or step-parent who refuses to contribute to college, even though they can afford it. Unfortunately, universities don’t have a “jerk dad won’t pay” fund to cover the difference. You hear stories about a family that can somehow find the extra money to send their kid to a big-name Ivy League school, but somehow don’t think they can afford a lower-ranked school. Colleges don’t have a “sorry we’re not Harvard” fund to cover the cost the families don’t want to spend. I’ve heard of parents who tell their children “you can go to any college you want, but I’ll only pay for it if you go to _______.” The schools that aren't ______ feel no obligation to give you more financial aid. If you think you might fall into any of these situations, do everything you can to resolve it soon.

Most colleges are not “need blind” when making acceptance decisions.

The average net cost of college--how much money people actually pay after financial aid and scholarships--isn't rising nearly as fast as the published sticker price. Universities, especially private ones, keep raising their prices a lot. They do this for a number of reasons: they want everyone to know what the education costs, even if you're not paying the full amount; they want to squeeze more money out of the rich kids who can afford the sticker price; they think that a higher price tag will make the school look more desirable. But the cost that people actually pay isn't nearly as high, and it's not rising as fast. Be prepared to invest a lot of money, but don't freak out when you see the sticker prices.