MOST FINANCIAL aid awards, either federal, state or from the colleges themselves, are based on a student's financial need. Need is computed using a standard formula that figures out how much a student, and/or his or her parents, can afford to contribute toward college. The difference between the cost of a particular college and the student/family contribution is considered the student's need.

Financial aid officers stress that all students who think they need help to pay for college should apply for aid, even if they think they won't qualify. If you don't apply, you definitely won't get anything.

The largest single source of aid is the federal government, which in fiscal 1989 spent almost $11.5 billion on student financial aid programs. Financial aid applications, which are available at college financial aid offices, are due by May 1 for the following school year, and may be sent in any time after January 1, the sooner the better. Deadlines may differ for state and institutional aid, so check with each particular college financial aid office.

These are the main federal aid programs:

Pell Grants: provides grants up to $2,300 per student per year to undergraduates, usually from the lowest-income families;

Supplemental Educational Opportunity Grants: provides up to an additional $4,000 per student per year in grants to exceptionally needy students;

College Work-Study: subsidizes jobs for undergraduates and graduate students, usually on campus, to help pay for educational expenses; the pay will vary according to the job and skills required;

Perkins Loans: Students can borrow up to $9,000 over four years at 5 percent interest; repayment starts six months after leaving school, and borrowers have up to 10 years to repay the loans;

Stafford Loans: First and second-year college students can borrow up to $2,625 a year, and $4,000 a year after that, at interest rates that start at 8 percent and rise to 10 percent after the first four years of repayment. The total amount undergraduates can borrow is $17,250.

PLUS/Supplemental Loans: These loan programs for parents and independent students are designed to meet any gap that is left after all other aid has been exhausted. Interest rates are set annually and are tied to financial market indicators; last year the rate was 12 percent. Borrowers can get up to $4,000 a year, or $20,000 total.

For questions about federal aid programs, call the Federal Student Aid Information Center at 1-800-333-INFO, during weekday working hours. In addition, college financial aid offices should have information on state aid programs and funds available directly from the college.