Gather all of your financial information from the previous year. For example, if you are looking to apply to college in 2009, you will need your 2008 financial documents. Specifically, you should find out the income, income taxes paid, social security, and bank holdings of both parents and the prospective student.
Visit the College Board EFC Calculator online, at the link below. This will allow you to more quickly calculate your EFC without lots of extra paperwork and math. Click on the "Next" button after filling out each step to proceed to the next page of information input.
Fill out your student's status, click "Next", and then be sure to select the "Both IM & FM" formula option on the following page before clicking "Next" again. This will allow you to get institutional and federal estimates of your EFC, which will provide a likely range within which your EFC will fall.
Fill out your family status, click "Next", and then carefully fill in all of the financial information on the Finances page. If you do not know your gross income for the year, click on the "Worksheet" link, and a window will pop up to help you calculate your gross income. Once you have filled out all the fields on this page, click "Next."
Look at the two EFC numbers that are derived from your information. One of them is a Federal determination more likely to be accurate for state schools, and one is Institutional and more likely to be accurate for private colleges. You should plan on paying at least as much as the EFC for each year of college you wish to attend.