How long before I get a green card?

Your question is more complex than you may realize. A U.S. Lawful Permanent Resident (holder of a "Green Card") may petition for her husband in the F2A visa category, but there is a backlog for available visas in that category - according to the April, 2015 Visa Bulletin issued by the U.S. Department of State, visas now are available for cases filed in August, 2013 for nationals from all countries except Mexico (for Mexican nationals, visas are now available for cases filed in July, 2013). While that may look like a delay of a bit more than two years, visa availability progresses and retrogresses, and the actual waiting time is likely to be longer than that. This means that if a Petition for Relative Alien were to be filed today, the foreign national would not be eligible to file an Adjustment of Status application for a couple of years, and then the adjudication process for the Adjustment of Status application may be expected to be around 4 - 7 months. Perhaps most important, if you are out of status, you would NOT be eligible to adjust status in the U.S. by virtue of being married to a Permanent Resident, and instead you would need to go abroad for consular processing. While in some instances with an F1 visa this might not apply, in general if one remains unlawfully present in the U.S. for 180 days or longer he becomes subject to a 3-year bar to re-entering the U.S., and if he is unlawfully present for a year or longer he becomes subject to a very harsh 10-year bar. In the case of a foreign national married to a U.S. citizen, however, the fact that the foreign national overstayed his visa will not render him ineligible to adjust status in the U.S. for that reason, the most appropriate plan may be for your wife to apply to become a naturalized U.S. citizen at the earliest possible time, and for her then to sponsor you in the Immediate Relative visa category. It would be wise to engage an immigration attorney to learn all of the relevant information about you and your soon-to-be wife, so that a full analysis can be made regarding eligibility, options and strategies. Some immigration law firms, including mine, offer legal services on a "flat fee" basis so that a client will know the total expense from the very beginning, and a few immigration law firms, including mine, offer an initial consultation free of charge. [Note: This communication is intended as general information and not specific legal advice, and this communication does not create an attorney-client relationship.]